Views), Spatial Visualization (Hidden Figures Test and the Purdue Spatial Visualization

Using an Argument-based Approach to Validity for Selected Tests of Spatial Ability in Allied Medical Professions Students

DISSERTATION

Presented in Partial Fulfillment of the Requirements for the Degree Doctor of Philosophy in the Graduate School of The Ohio State University

Terri Ann Bruckner, M.A.

Graduate Program in Education

The Ohio State University

2013

Dissertation Committee:

Dorinda Gallant, Advisor

Ann O’Connell

Laura Harris

Copyrighted by

Terri Ann Bruckner

2013

Abstract

Spatial ability is a cognitive skill required for success in many professions. Those in the Allied Medical professions utilize this skill in the performance of many of their daily tasks. Understanding the nature of this ability in Allied Medical educational programs may allow educators to improve the delivery of material or develop training material for students who have low levels of spatial ability. In order to assess spatial ability in Allied Medical students, valid instruments are needed. This study used the argument-based approach to examine the validity evidence for six tests of spatial ability in a group of 128 Allied Medical students. Tests were chosen to assess spatial perception

(Cube Comparison Test and The Purdue Spatial Visualization Test Visualization of

Views), spatial visualization (Hidden Figures Test and The Purdue Spatial Visualization

Test Visualization of Developments), and mental rotation (Mental Rotations Test and The

Purdue Spatial Visualization Test Visualization of Rotations). Evidence is presented to support the assertions that some of these tests can be interpreted as spatial ability measures, but the assertions that the chosen tests measure spatial perception, spatial visualization, and mental rotation abilities was not satisfied.

Dedication

To my husband, Mike, your love and support made it possible for me to get this far. To my son David and his family, thank you for your willingness to share me with my pursuit of a graduate degree. To Brian and Rebecca Welch—thanks for your encouragement and our Friday nights. Thanks to my parents, Mary and Roger Johnson, and to my sister Tammy Fisher, for all of your encouragement. Melinda, thanks for making graduate school fun.

iii

Acknowledgments

I would like to thank Dr. Dorinda Gallant for her help and constant support.

Without your encouragement, this would never have been possible. I would also like to thank Drs. Ann O’Connell and Laura Harris for serving as my committee members and for their suggestions for improving this document. I want to express my appreciation to

Dr. Ayres D’Costa, who encouraged me to pursue my doctorate and helped me in refining my topic. I also want to sincerely thank Deb Zabloudil, who wouldn’t let me quit.

Vita

June 1974 ...... West Liberty-Salem High School

1978 ...... B.S., Allied Medical Professions, The Ohio

State University

1988 ...... M.A., Education, The Ohio State University

1985 to present ...... Clinical Instructor, School of Health and

Rehabilitation Sciences, The Ohio State

University

Fields of Study

Major Field: Education

Table of Contents

Abstract ...... ii

Dedication ...... iii

Acknowledgments...... iv

Vita ...... v

Fields of Study ...... v

Table of Contents ...... vi

List of Tables ...... xi

List of Figures ...... xv

Chapter 1: Introduction ...... 1

Allied Medical Professionals and Their Associated Spatial Tasks ...... 4

Athletic Training...... 5

Health Information Management and Systems ...... 6

Medical Dietetics ...... 6

Occupational Therapy ...... 7

Significance and Purpose of this Study ...... 16

Organization of the Dissertation ...... 22

Chapter 2: Review of the Pertinent Literature ...... 23

Validity ...... 23

Unified Theory of Validity ...... 28

The History of Research Related to Spatial Ability ...... 32

What is Spatial Ability? ...... 39

Individual Differences in Spatial Ability ...... 46

Biologic Factors Related to Individual Differences in Spatial Ability ...... 47

Environmental Factors Related to Individual Differences in Spatial Ability ...... 55

Tests of Spatial Ability ...... 58

The Purdue Spatial Visualization Test (PSVT) ...... 60

Hidden Figures Tests ...... 64

Mental Rotations Test (MRT) ...... 66

The Cube Comparison Test ...... 69

Studies of Spatial Ability in Healthcare ...... 70

Summary ...... 79

Chapter 3: Design and Methods ...... 84

Population and Sample ...... 86

vii

Population ...... 86

Sample ...... 88

Instrumentation...... 89

Tests to Measure Spatial Perception Ability ...... 90

Tests to Measure Spatial Visualization Ability ...... 95

Tests to Measure Mental Rotation Ability ...... 100

The Spatial Experience Questionnaire ...... 105

Data Collection ...... 105

Data Analysis ...... 107

Statistical Analysis Assumption Checking ...... 118

Chapter 4: Results ...... 120

Spatial Skills in Allied Medical Professions ...... 120

Validation Evidence ...... 127

Validation Evidence for the Cube Comparison Test Results ...... 129

Validation Evidence for the Spatial Experience Questionnaire ...... 139

Validation Evidence for the PSVT Visualization of Views Test Results...... 142

Validation Evidence for the Spatial Experience Questionnaire ...... 148

Validation Evidence for the PSVT Visualization of Developments Test ...... 150

Validation Evidence for the Spatial Experience Questionnaire ...... 161

viii

Validation Evidence for the Hidden Figures Test ...... 163

Validation Evidence for the Spatial Experience Questionnaire ...... 169

Validation Evidence for the PSVT Visualization of Rotations Test ...... 170

Validation Evidence for the Spatial Experience Questionnaire ...... 176

Validation Evidence for the Mental Rotations Test ...... 177

Validation Evidence for the Spatial Experience Questionnaire ...... 187

Additional Validation Evidence for the Spatial Experience Questionnaire ...... 188

Chapter 5: Discussion and Conclusions ...... 190

Spatial Skills in Allied Medical Professions ...... 191

Validation Evidence for the Cube Comparison Test ...... 194

Validation Evidence for the Visualization of Views subtest of the Purdue Spatial

Visualization Test ...... 199

Validation Evidence for the Visualization of Developments Subtest of the Purdue

Spatial Visualization Test...... 203

Validation Evidence for the Hidden Figures Test ...... 207

Validation Evidence for the Visualization of Rotations Subtest of the Purdue Spatial

Visualization Test battery...... 211

Validation Evidence for the Mental Rotations Test ...... 215

Limitations ...... 219

Conclusions and Recommendations for Future Research ...... 222

References ...... 228

Appendix A: Spatial Tasks for Athletic Training ...... 244

Appendix B: Spatial Tasks for Health Information Management and Systems ...... 255

Appendix C: Spatial Tasks for Medical Dietetics...... 261

Appendix D: Spatial Tasks in Occupational Therapy...... 265

Appendix E: Spatial Tasks in Radiologic Science ...... 273

List of Tables

Table 1. Spatial Tests Used in this Study ...... 11

Table 2. Descriptions of the Allied Medical Professions Included in this Study ...... 87

Table 3. Demographic Information for Sample ...... 89

Table 4. Tasks Requiring the Use of Spatial Perception ...... 122

Table 5. Tasks Requiring Spatial Visualization ...... 124

Table 6. Tasks Requiring Mental Rotation ...... 126

Table 7. Score Information for the Cube Comparison Test, Version A ...... 131

Table 8. Score Information for the Cube Comparison Test, Version B ...... 133

Table 9. Pearson Correlations between the Cube Comparison Test and the Mental

Rotations Test ...... 136

Table 10. Pearson Correlations between the Cube Comparison Test and the PSVT

Visualization of Views Test ...... 137

Table 11. Statistically Significant Spearman Correlations between Extent of Participation in Spatial Activities and Cube Comparison Test Scores ...... 141

Table 12. Statistically Significant Spearman Correlations between Extent of Enjoyment in Spatial Activities and Spatial Test Scores ...... 142

Table 13. Score Information for the Visualization of Views Subtest of the PSVT ...... 144

Table 14. Pearson Correlation between the PSVT Visualization of Views Test and the

Mental Rotations Test ...... 146

Table 15. Pearson Correlations between the Cube Comparison Test and the PSVT

Visualization of Views Test ...... 147

Table 16. Statistically Significant Spearman Correlations between Extent of Participation in Spatial Activities and Visualization of Views Test Scores...... 149

Table 17. Statistically Significant Spearman Correlations between Extent of Enjoyment in Spatial Activities and Visualization of Views Test Scores...... 150

Table 18. Descriptive Statistics and Scoring Information for Version A of the PSVT

Visualization of Developments Subtest ...... 152

Table 19. Descriptive and Score Information for the Visualization of Developments

Subtest of the PSVT, Version B ...... 155

Table 20. Pearson Correlations between the PSVT Visualization of Developments Test and the Mental Rotations Test ...... 157

Table 21. Pearson Correlation between the PSVT Visualization of Developments Test and the Hidden Figures Test ...... 158

Table 22. Statistically Significant Spearman Correlations between Extent of Participation in Spatial Activities and Visualization of Developments Tests Scores ...... 161

Table 23. Statistically Significant Spearman Correlations between Extent of Enjoyment in Spatial Activities and Visualization of Developments Test Scores ...... 162

Table 24. Descriptive and Scoring Information for the Hidden Figures Test ...... 165

xii

Table 25. Pearson Correlation between the Hidden Figures Test and the Mental

Rotations Test ...... 167

Table 26. Pearson Correlation between the PSVT Visualization of Developments Test and the Hidden Figures Test ...... 168

Table 27. Statistically Significant Spearman Correlations between Extent of Enjoyment in Spatial Activities and Hidden Figures Test Scores ...... 170

Table 28. Score Information for the Visualization of Rotations Subtest of the PSVT .. 172

Table 29. Pearson Correlations between the PSVT Visualization of Rotations Test and the Mental Rotations Test ...... 174

Table 30. Statistically Significant Spearman Correlations between Extent of Participation in Spatial Activities and Visualization of Rotations Test Score ...... 176

Table 31. Statistically Significant Spearman Correlations between Extent of Enjoyment in Spatial Activities and Visualization of Rotations Test Score ...... 177

Table 32. Descriptive Statistics and Scoring Information for the Mental Rotations Test,

Version A ...... 180

Table 33. Descriptive Statistics and Score Information for the Mental Rotations Test,

Version B ...... 182

Table 34. Pearson Correlations Between all Tests of Spatial Ability in this Study...... 184

Table 35. Statistically Significant Spearman Correlations between Extent of Participation in Spatial Activities and Scores on the Mental Rotations Test ...... 187

Table 36. Statistically Significant Spearman Correlations between Extent of Enjoyment in Spatial Activities and Scores on the Mental Rotations Test ...... 188

xiii

Table 37. Summary of Validity Evidence for Spatial Tests ...... 224

Table 38. Spatial Tasks in Athletic Training ...... 244

Table 39. Spatial Tasks in Health Information Management and Systems ...... 255

Table 40. Spatial Tasks for Medical Dietitians ...... 261

Table 41. Spatial Tasks in Occupational Therapy ...... 265

Table 42. Spatial Tasks in Radiologic Science ...... 273

xiv

List of Figures

Figure 1. Example Item from the Visualization of Views Subtest of the Purdue Spatial

Visualization Test ...... 92

Figure 2. Example Item from the Cube Comparison Test ...... 94

Figure 3. Example Item from the Hidden Figures Test ...... 97

Figure 4. Example Item from the Visualization of Developments Subtest of the Purdue

Spatial Visualization Test ...... 99

Figure 5. Example Item from the Visualization of Rotations Subtest of the Purdue

Spatial Visualization Test ...... 101

Figure 6. Example Item from the Mental Rotations Test ...... 103

Figure 7. Scores on Version A of the Cube Comparison Test ...... 130

Figure 8. Scores on Version B of the Cube Comparison Test ...... 132

Figure 9. Variations in Performance on the Cube Comparison Test, Version A...... 139

Figure 10. Variations in Performance on the Cube Comparison Test, Version B ...... 139

Figure 11. Score Distribution of the PSVT Visualization of Views Subtest ...... 143

Figure 12. Gender Differences on the Visualization of Views Test ...... 148

Figure 13. Score Distribution of the PSVT Visualization of Developments Subtest,

Version A ...... 151

Figure 14. Score Distribution of the PSVT Visualization of Developments Subtest,

Version B ...... 154

Figure 15. Variations in Performance on the Visualization of Developments Test,

Version A ...... 160

Figure 16. Variations in Performance on the Visualization of Developments, Version B

...... 160

Figure 17. Score Distribution of the Hidden Figures Test ...... 164

Figure 18. Variations in Performance on the Hidden Figures Test ...... 169

Figure 19. Score Distribution of the PSVT Visualization of Rotations Test ...... 171

Figure 20. Variations in Performance on the Visualization of Rotations Test ...... 176

Figure 21. Score Distribution for the Mental Rotations Test, Version A ...... 179

Figure 22. Score Distribution for the Version B of the Mental Rotations Test ...... 181

Figure 23. Variations in Performance on the Mental Rotations Test, Version A ...... 186

Figure 24. Variations in Performance on the Mental Rotations Test, Version B ...... 186

xvi

Chapter 1: Introduction

Spatial ability is a broad term that relates to how individuals interact with and interpret their environment. Over the past 90 years, many researchers have attempted to define spatial ability. Unfortunately, there is still debate regarding whether this is a unique ability, or a combination of abilities. If it is a combination of abilities, there are still questions as to what factors are involved. In various studies, spatial ability is considered to be a group of related skills distinctly different from other cognitive skills such as verbal reasoning (Keehner, Cohen, Hegarty, & Montello, 2004; McGee, 1979).

Characteristics of this skill include the ability to generate visual images, perceive spatial arrangements, construct and deconstruct mental visual images, retain images in the mind, and transform, manipulate, or rotate images mentally (Barratt, 1953; Cohen & Hegary,

2007; Guilford, Fruchter, & Zimmerman, 1952; Guilford & Lacey, 1947; Hegarty &

Kozhevnikov, 1999; Kelley, 1928; Kesner & Linzey, 2005; Kyllonen, Lohman, & Snow,

1984; Michaelides, 2003; Thurstone, 1938). Eliot (2002) used a broader term for spatial ability, referring to it as a type of intelligence. He discussed the magnitude of this type of intelligence by stating:

I am convinced that spatial intelligence has been significantly underestimated in the role it plays in our everyday lives. Spatial intelligence is fundamental in the sense that it may operate at any given moment at several levels of human consciousness and, in 1 combination with other cognitive functions, it may also contribute both to how we learn to process different kinds of information and how we develop strategies for solving many types of everyday problems. It is pervasive in the sense that we use it whenever we act upon information about the positional, distance, and directional relationships of people and objects in our daily lives. In my opinion, we have only begun to appreciate the fundamental and pervasive role this intelligence plays in our everyday lives (Eliot, 2002, p. 479).

Numerous studies in the early part of the twentieth century served to establish the existence of a spatial ability factor (El Koussy, 1935; Guilford, Fruchter, & Zimmerman,

1952; Guilford & Lacey, 1947; Kelley, 1928; McFarlane, 1925; Thurstone, 1924). Over the past 70-80 years, hundreds of researchers have worked to further define, categorize, and explain this ability. Most authors agree that spatial ability, sometimes referred to as spatial intelligence, includes the ability to mentally visualize, manipulate, or transform objects in space as well as the ability to orient one’s self, or an object in relationship to one’s self (Eliot, 2000; Guilford, 1967; Guilford & Hoepfner, 1971; Hyde, Geiringer, &

Yen, 1975; Linn & Petersen, 1985; Lohman, 1989; McGee, 1979).

In addition, researchers have attempted to determine if spatial ability is a unitary concept, or if it is a variety of related abilities. Many categories of spatial ability have been proposed. Some of the most widely studied are spatial orientation, spatial perception, spatial visualization, and mental rotation. Linn and Petersen (1985), and

Voyer, Voyer, and Bryden (1995) proposed three categories of spatial ability: (a) spatial perception, which involves an ability to determine relationships with respect to one’s own

2 body; (b) spatial visualization, involving tasks that require complex multistep manipulations; and (c) the mental rotation of imagined figures.

Spatial ability appears to be an essential skill for those who are involved in science and math related professions. This skill has been studied in engineering students, chemistry students, and medical students (Berbaum, Smoker, & Smith, 1985; Bodner &

Guay, 1997; Carter, LaRussa, & Bodner, 1987; Garg, Norman, & Sperotable, 2001;

Hegarty, Keehner, Cohen, Montello, & Lippa, 2007; Martin-Dorta, Saorin, & Contero,

2008). It has been found that those who do better on tests of spatial skills tend to perform better in science and math related academic courses (Baker & Talley, 1972; Battista,

1990; Edens & Potter, 2007; Eisenberg & McGinty, 1977; Fennema & Sherman, 1977;

Guay & McDaniel, 1977).

Furthermore, studies have been done which allude to the relationship between spatial ability and ability in certain academic, professional, and cultural endeavors

(Lunneborg & Lunneborg, 1984; McDaniel, Guay, Ball, & Kolloff, 1978; Newcombe,

Bandura, & Taylor, 1983; Zimowski & Wothke, 1988). In studies of college students, men who enrolled in courses such as architecture, calculus, chemistry, music, art, engineering, and drafting did well on spatial tests (Bodner & Guay, 1997; Carter,

LaRussa, & Bodner, 1987; Edens & Potter, 2007; Guay, 1980; Hegarty & Kozhevnikov,

1999; Johnson & Bouchard, 2007). Women who enrolled in astronomy, physics, architecture, high level math, and drafting courses also scored well on spatial tests (Olson

& Eliot, 1986). Guay (1978) found that college students who scored highly on a spatial

3 questionnaire scored higher on a mental rotation test, but not on other tests of spatial ability.

Allied Medicine (e.g. Athletic Training, Circulation Technology [Perfusion],

Health Sciences, Health Information Management and Systems [HIMS], Medical

Dietetics, Medical Laboratory Science [sometimes referred to as Medical Technology],

Occupational Therapy, Physical Therapy, Radiologic Sciences, and Respiratory Therapy) is a term that encompasses the various professions involved in healthcare who support and consult with physicians and nurses. Students must be proficient in a variety of science courses to practice in their chosen fields. In addition, there are crucial spatial skills that must be mastered for both didactic and clinical courses.

Allied Medical Professionals and Their Associated Spatial Tasks

Many of the routine tasks performed by health care professionals seem to have a spatial component. Understanding the nature of the required spatial skills may inform educators as they develop curricula and ultimately allow those health professionals to do their jobs more efficiently. The roles of these medical professionals can be categorized and analyzed according to their spatial nature. The following section briefly describes the five professions to be investigated in this study.

Athletic Training

Athletic Trainers (AT) work with physicians, athletic personnel, patients and their families, and other medical professionals, to provide care in a variety of settings. These professionals are skilled in methods of risk management and injury prevention. When an athlete is injured the AT must be able to examine, diagnose, and recommend the appropriate care for the injury (Athletic Training, 2012). Examination of patients requires keen observational skills. The trainer must be able to recognize visual clues related to health and injury. These clues may be overt or covert and may require that visual information be mentally manipulated. Internal structures must be mentally visualized, and normal versus abnormal physical patterns evaluated and acted upon.

Gravitational or spatial orientation is a desirable skill for this group of professionals.

They must be able to use, instruct, and assist others in using exercise equipment, and they must be able to adjust their client’s and their own body mechanics (Athletic Trainers,

2010). Athletic Trainers generally complete courses in anatomy and physiology, biology, chemistry, human nutrition, and pharmacology in addition to math, humanities courses, and athletic training courses.

Health Information Management and Systems

This profession focuses on the business aspects of healthcare. A career in this field appeals to those with interests in healthcare, business, and information technology.

Health information management professionals work in a variety of healthcare or commercial settings. Major responsibilities include collection, storage, management, and retrieval of healthcare data. Communication is another key component of this occupation

(Health Information Management and Systems, 2012). Visualization of anatomy and physiology are helpful skills for these professionals. They must also be able to recognize patterns and disembed patterns from medical data, graphs, and charts (Medical Records and Health Information Technicians, 2010). Preparatory courses for this profession include biology or chemistry, anatomy and physiology, pharmacology, and computer information courses.

Medical Dietetics

These professionals practice medical and community nutrition therapy and work with patients in long term care. They have a heavy background in science courses such as anatomy and physiology, chemistry, biology, biochemistry, and microbiology to prepare for the occupation. Professionals in this occupation must be able to recognize patterns in laboratory specimens, interpret radiographic images, and interact with patients

6 and clients (Dietitians and Nutrionionists, 2010). Visualization of anatomic structures and physiologic processes are also key skills for these professionals. They may practice in medical facilities, governmental departments, or commercial enterprises.

Communication and consultation are essential skills (Medical Dietetics, 2012).

Occupational Therapy

Occupational Therapists (OT) work with other members of the healthcare team to assess and help patients/clients maintain or regain the ability to function independently.

Their clients may have physical impairments or diseases which restrict or limit their day- to-day activities (Occupational Therapy, 2012). Therapists must assess their clients’ health and well-being which frequently requires the ability to visualize internal anatomy as well as the ability to spatially orient their own bodies in relation to their client.

Visualization and spatial orientation are further required as they plan and develop adaptive devices for various types of disabilities or diseases (Occupational Therapists,

2010). Prerequisite science courses for students in this profession include biology, anatomy, and physiology.

Radiologic Sciences

Radiologic Sciences professions include those related to medical imaging and those related to the use of radiation to provide therapeutic treatment for disease.

Radiologic Technology and Medical Imaging are other terms used for those engaged in the science of using radiation (x-ray, magnetism, and ultrasound) to produce images of the tissues, organs, bones, and vessels of the body for both diagnostic and therapeutic purposes (Radiologic Sciences and Therapy, 2012). As a practicing educator in this field, the author knows that those who specialize in the various facets of medical imaging must be able to visualize normal as well as abnormal or diseased anatomy. Preparing patients for imaging procedures requires the ability to orient themselves and their patients in relation to the imaging equipment. Evaluation of images requires the ability to visualize depth, and with some types of images the ability to mentally rotate a visualized anatomic structure into a different imaging plane (Radiologic Technologists, 2010). Students in a radiologic sciences program require a background in physics, biology, anatomy, and physiology.

Validity Evidence for Instruments Used to Evaluate Spatial Ability

There are hundreds of tests of spatial ability that have been used over the past 100 years. A large sampling of these tests was compiled by Eliot and Smith (1983), and classified into ten task categories. Meta-analyses such as those by Linn and Petersen

(1985) and Voyer, Voyer, and Bryden (1995) have categorized spatial ability by the skills that tests seem to measure. These meta-analyses examined studies from children as young as four years old and adults as old as their mid-eighties. No specific information was included in either of these studies as to the disciplines that were studied. While no

8 specific validation evidence was offered by these two studies, they did categorize spatial tests as to the skills they were purported to measure based on reported gender differences.

Tests that measured mental rotation included the Space Relations subtest of the Primary

Mental Abilities Test by Thurstone, the Flags and Cards Rotation Tests, generic mental rotations tests, and the Vandenberg and Kuse Mental Rotations Test. Tests that measured skills in the category of spatial perception included the Rod-and-Frame Test and the

Water Level Test. Tests that measured skills related to spatial visualization included: paper folding tests, surface developments tests, the Spatial Relations subtest of the

Differential Aptitude Test (DAT-SR), the Embedded Figures Test, the Hidden Figures

Test, the children’s version of the Embedded Figures Test, the Identical Blocks Test, the

Paper Form Board Test, and the Block Design subtest of the Wechsler Adult Intelligence

Scale.

Although hundreds of spatial tests are available, validity evidence is scarce.

Validity is defined in the Standards for Educational and Psychological Testing (1999) as

“the degree to which evidence and theory support the interpretation of test scores entailed by proposed uses of tests” (p. 9). Put another way, validation lends evidence that an instrument measures what it professes to measure (Huck, 2004; Knapp & Mueller, 2010;

Messick, 1989; Salkind, 2004). In any discussion of validity, it is critical to realize that it is not the instruments themselves that are being validated, but the uses and interpretations of the results of these instruments that are being examined (Babbie, 1995; Kane, 2006;

Knapp & Mueller, 2010; Messick, 1989). Thus, in order to interpret results from spatial tests for Allied Medical students, evidence of validity must be examined.

A search of the medical literature found validation studies with a few researcher- developed tests for teaching anatomy or physician skills (Friedman, Dev, Dafoe, Murphy,

& Felciano, 1993; Smoker, Berbaum, Luebke, & Jacoby, 1984). The following databases were searched to attempt to locate information on validation studies of spatial tests in

Allied Medical Professions: Academic OneFile, Academic Search Complete,

MasterFILE Complete, Newspaper Source Plus, OAIster, Oxford Scholarship Online,

WorldCat.org, and Medline. No validation studies in any of the Allied Medical professions were found for any published spatial test.

Tasks that seem especially pertinent to those in the Allied Medical Professions are spatial visualization, spatial perception and orientation, and mental rotation. The tests chosen to evaluate Allied Medical students in this study (see Table 1) are The Hidden

Figures Test for spatial visualization (Ekstrom, French, & Harman, 1976), the Cube

Comparison Test for spatial perception and orientation (Ekstrom, French, & Harman,

1976), the three-part Purdue Spatial Visualization Test for spatial orientation, spatial visualization, and mental rotation (Guay, 1980), and the Mental Rotations Test for mental rotation (Peters, Laeng, Latham, Jackson, Zaiyouna, & Richardson, 1995; Vandenberg &

Kuse, 1978). These tests were chosen because some validity evidence was available in the literature, and because each has been used in previous studies of spatial ability in college students. A brief description of each test is provided below. Complete descriptions for each of these tests are presented in Chapter Three of this document.

Spatial Skill to be Evaluated Spatial Test

Spatial Visualization The Hidden Figures Test

Spatial Visualization The Visualization of Developments Subtest

of the Purdue Spatial Visualization Test

Spatial Perception The Cube Comparison Test

Spatial Perception The Visualization of Views Subtest of the

Purdue Spatial Visualization Test

Mental Rotation The Mental Rotation Test

Mental Rotation The Visualization of Rotations subtest of

the Purdue Spatial Visualization Test

Table 1. Spatial Tests Used in this Study

The Hidden Figures Test and other embedded figures tests have been frequently used as tests of spatial visualization (Davis & Eliot, 1994; Hassler, Birbaumer, & Feil,

1985; Linn & Petersen, 1985; Lord, 1990; Voyer, Voyer, & Bryden, 1995). These tests have reported internal consistency and split-half reliabilities ranging from .8 to .95

(Ekstrom, French, & Harman, 1976; Hegarty, Montello, Richardson, Ishikawa, &

Lovelace, 2006; Hyde, Geiringer, & Yen, 1975). These types of tests have also been found to correlate significantly with other tests of spatial ability, both large and small scale demonstrating construct-related validity evidence (Hegarty, Montello, Richardson,

Ishikawa, & Lovelace, 2006). There are conflicting reports as to whether the Hidden

Figures test can demonstrate the expected gender differences in spatial ability (Linn &

Petersen, 1985; Massa, Mayer, & Bohon, 2005; Voyer, Voyer, & Bryden, 1995), but this is not unexpected since spatial visualization has not demonstrated consistent significant gender differences.

The Cube Comparison Test has been designated as a test of spatial orientation by

Ekstrom, French, and Harman in the Kit of Factor Referenced Cognitive Tests (1976). In a group of 11th and 12th grade students, the reliability (type of reliability was not specified) was reported to be .77 for both males and females, and .84 in college students

(Ekstrom, French, & Harman, 1976). This test has been used as part of a battery to determine high and low spatial ability in a group of undergraduate students taking a biology course (Lord, 1990) and as a measure of spatial orientation in a study of 83 adolescent pairs of twins to evaluate sex-linked gender differences in spatial orientation

(Jardine & Martin, 1984), however no reliability or validity evidence was included in this study.

The Mental Rotations Test (Vandenberg & Kuse, 1978) is a widely accepted test for spatial ability. Many authors have reported evidence related to the validity of interpretations and uses of this test. The Mental Rotations Test has been shown to correlate significantly with other tests of spatial ability such as the Spatial Relations subtest of the Primary Mental Abilities Test (Voyer, et al., 2006), the Cards Rotation Test

(Cherney, 2008), the Spatial Relations subtest of the Differential Aptitude Test

(Vandenberg & Kuse, 1978), and the Embedded and Hidden Figures Tests (Ekstrom,

French, & Harman, 1976). Vandenberg and Kuse (1978) reported test-retest reliability of

.83 and internal consistency reliability of .88 when this test was given to large samples of

12 adolescents and adults, and Vandenberg, Kuse, and Vogler (1985) reported split-half reliability of .64 in a study of 56 college undergraduates. Internal consistency reliability of .91for a redrawn version of the Mental Rotations Test was found in a group of 157 college undergraduates (Voyer, et al., 2006). Hegerty et al. (2006) reported internal reliability of .88 in a group of 221 adult volunteers.

Furthermore, spatial tests should correlate well with mathematics and science grades which The Mental Rotations Test has been shown to do. Peters et al. (1995) found that students from science-based academic programs scored significantly better on their redrawn Mental Rotations Test than students from arts and humanities programs. In a later study, similar results for academic program type were found in students from

Canada, Germany, and Japan (Peters, Lehmann, Takahira, Takeuchi, & Jordan, 2006).

This test also correlates highly with large scale and environmental tests of spatial ability

(Hegarty, Montello, Richardson, Ishikawa, & Lovelace, 2006). Spatial ability is seen to be a separate ability from verbal reasoning and spatial tests should exhibit small correlations with these types of tests as well as tests for English and Humanities courses.

As expected, low correlations are seen between this test and tests of verbal reasoning

(Vandenberg & Kuse, 1978). Additionally, spatial ability scores tend to favor males, and this test almost always demonstrates this gender difference in scores (Cherney, 2008;

Geiser, Lehmann, & Eid, 2008; Kaufman, 2007; Linn & Petersen, 1985; Peters, Laeng,

Latham, Jackson, Zaiyouna, & Richardson, 1995; Stumpf, 1993; Vandenberg & Kuse,

1978; Voyer, Rodgers, & McCormick, 2004; Voyer, Voyer, & Bryden, 1995). In fact,

13 the effect size for gender differences in performance on this test have been reported to range from .7 to .95 (Masters, 1998; Voyer, Voyer, & Bryden, 1995).

The Purdue Spatial Visualization Test is a three-part test consisting of a

Visualization of Views subtest, a Visualization of Developments subtest, and a

Visualization of Rotations subtest. Composite reliability has been reported to be as high as .92, with a range of .56 to .87 for the individual subtests (Battista, 1990; Guay, 1978;

Guay, 1980). It has been found to correlate significantly with other spatial tests such as the Spatial Relations subtest of the Differential Aptitude Test and the Shepard and

Metzler mental rotations test (Kovac, 1989). It has also shown the expected gender differences favoring males, and to predict performance in college chemistry and engineering courses (Bodner & Guay, 1997; Guay, 1980; Sorby & Baartmans, 2000).

These characteristics tend to suggest the construct validity for the use of this test in measuring spatial ability.

The Spatial Experience Questionnaire (McDaniel, Guay, Ball, & Kolloff, 1978) contains 25 items and asks respondents to indicate their level of participation and their level of enjoyment for each of these items. It is described as being “developed to measure the extent of participation in and enjoyment of experiences that might be relevant to the development of spatial abilities” (p. 1). The authors of the questionnaire compiled this list of 25 activities as those which “young adults might have engaged at some time while growing up” (McDaniel, Guay, Ball, & Kolloff, 1978, p. 2). In a study of 242 college students, respondents were asked to classify each activity according to level of both participation and enjoyment. The authors found the survey resulted in

14 significant differences in participation scores between high and low spatial groups for both men and women, and in enjoyment scores for high and low spatial groups for men.

Kane’s Interpretive and Validity Argument within Validity and Validation

Validation and validity have been categorized in many ways. Kane (2006) described the historical evolution of validity theory from criterion to content to construct models over the last 90 years. He went on to discuss the melding of these methods in the

1970s and 1980s, in which Cronbach, and later Messick advocated a unified theory of validity. A unified theory of validity was described by Kane as emphasizing “the need for an overall evaluation of validity involving multiple kinds of evidence” (Kane, 2006, p. 20). Kane (2006) described the unified theory of validity as “quite appealing as a conceptual framework for validity” but noted that it “didn’t provide clear guidance for validation of a test-score interpretation or use” (p. 21). His argument-based framework for validation involved two steps: the specification of interpretive arguments and the uses of scores, and an evaluation of the plausibility of these proposed interpretations and uses

(Kane, 2011). He called these the interpretive argument and the validity argument.

According to Kane (2006), the interpretive argument “specifies the proposed interpretations and uses of test results by laying out the network of inferences and assumptions leading from the observed performances to the conclusions and decisions based on the performances” (p. 23). The validity argument then consists of an evaluation of the plausibility of the inferences and assumptions put forth in the interpretive

15 argument. This framework is similar to the approach adopted by the 1999 Standards for

Educational and Psychological Testing.

The interpretive argument commonly starts with an examination of scoring. This interpretation “claims relatively little and requires relatively little evidence for its support, mainly evidence that the scoring rule is reasonable and that it has been applied appropriately and consistently” (Kane, 2011, p. 8). A second inference may involve generalization. Evidence for this inference would involve reliability or generalizability studies to support claims for validity. Extending the interpretive argument further may provide evidence that information from the scores can be extrapolated to broader domains. Criterion-related studies or analyses of the commonalities between assessment performance and performance in wider domains would supply evidence to support this inference. Often, a final inference is related to decision-making based on the results of the responses on the measurement instruments (Kane, 2006; Kane, 2011). This framework will be used for this research study and is more fully described in Chapter

Two.

Significance and Purpose of this Study

Spatial ability has been established as a type of intellectual ability, distinct from other abilities. It has been shown to differ across genders, and be affected by life experiences. Many studies have been done with physicians and dental professionals to evaluate the need for, existence of, and levels of spatial ability in various healthcare

16 occupations. In the dental profession, tests of spatial ability are used as criteria for admission. Some physician training programs have also investigated the usefulness of including spatial tests as part of the admission process (Hegarty, Keehner, Cohen,

Montello, & Lippa, 2007). Other researchers have examined how spatial ability is related to skills such as surgery or interpreting radiologic images (Anastakis, Hamstra, &

Matsumoto, 2000; Berbaum, Smoker, & Smith, 1985; Garg, Norman, & Sperotable,

2001; Keehner, Tendick, Meng, Anwar, Stoller, & Duh, 2004; Nilsson, Hedman, &

Ahlqvist, 2007). While most physician programs have, to date, rejected using tests of spatial ability as a component of admission criteria, it has been established that this intellectual skill is highly useful in medical fields such as surgery and radiology

(Anastakis, Hamstra, & Matsumoto, 2000; Hegarty, Keehner, Cohen, Montello, & Lippa,

2007; Risucci, 2002; Smoker, Berbaum, Luebke, & Jacoby, 1984; Wantzel, Hamsta,

Anastakis, Matsumoto, & Cusimano, 2002).

Allied Medical professionals are also engaged in highly visual occupations, and many types of spatial skills are necessary in order to efficiently perform the necessary tasks required for these jobs. A search of the Medline and CINAHL databases using the keywords “spatial ability” with the keywords for the various Allied Medical Professions examined in this study revealed only one study examining this skill, a study examining the relationship between spatial perception and achievement in sonography students

(Clem, Anderson, Donaldson, & Hdeib, 2010).

The overall goal of this study is two-fold: (a) to determine the extent to which validity evidence can be established for currently available instruments for use with

Allied Medical professionals and (b) to examine spatial abilities in Allied Medical professionals. Allied Medical professionals must be proficient in a variety of spatial tasks in the performance of their occupational duties. As a practitioner and educator in an

Allied Medical profession, the author knows that some tasks involve the ability to visualize information; internal anatomic structures cannot be seen, but must be mentally pictured to perform tasks such as patient assessment and prepare for radiographic imaging. Other tasks require that the practitioner be able to mentally orient themselves, their patients, or their equipment. Patients with disabilities or injuries cannot always be placed in textbook positions for therapeutic treatments. Professionals must be able to orient themselves and their equipment to function efficiently for patients in spite of these difficulties. This may require the construction of mental images that relate up/down and/or left/right visualization of machinery or persons. Still other tasks require that medical professionals be able to mentally rotate or transform verbal or figural information. One example involves cross-sectional images used in the diagnosis and evaluation of many types of diseases. Anatomy is learned in frontal, lateral (from the side), or three-dimensional space. Sectional images require that the information be rotated mentally in order to identify the anatomic structures as they are presented in this unique format.

A deeper understanding of the above skills may allow educators to enhance learning and develop alternative instructional opportunities for students in their professional programs. Additionally, remedial educational modules could be developed to potentially help students strengthen their spatial skills. If there are identifiable

18 differences in spatial skills in these various occupations, there may be implications for career counseling. Potential students with lower levels of spatial ability might need additional course work of a spatial nature to ensure success in their chosen career path, or future studies may investigate the need for spatial tests as part of admission criteria for some healthcare educational programs. To add to the limited research on spatial ability in this population, tests that accurately measure spatial abilities must be found, and identification of relevant spatial experiences must be examined. Interpretation of any measurement tool’s scores can only be initiated after evidence of validity has been established.

Moreover, understanding the nature of the spatial abilities required for each Allied

Medical profession could be important in other ways. Spatial ability could be used as a criterion for admission into some of these programs. Courses could be assessed for the degree and level of spatial ability needed for successful completion. Educators could evaluate their teaching methods to take spatial ability into account in their course planning. Students could be given special assignments to attempt to improve their spatial skills in didactic and clinical courses.

Research Questions

Research Question 1: What spatial skills are used by Allied Medical Professionals in the accomplishment of their occupational duties? Which of these skills are shared across the

19 professions? Do the professions differ in their reliance on spatial perception, spatial visualization, or mental rotation abilities?

Research Question 2: To what extent is validity evidence provided for the use of the

Mental Rotations Test, the Purdue Spatial Visualization Test (PSVT), the Cube

Comparison Test, and The Hidden Figures Test to measure spatial ability in Allied

Medical students?

In order to examine this question, the following assumptions addressing the various aspects of the interpretive argument will be used:

1. Scores on the Cube Comparison, Visualization of Views, Visualization of

Developments, Hidden Figures, Visualization of Rotations, and Mental

Rotations Tests will be able to differentiate level of spatial ability for the

sample of Allied Medical students in this study.

2. Scores on the Cube Comparison, Visualization of Views, Visualization of

Developments, Hidden Figures, Visualization of Rotations, and Mental

Rotations Tests will demonstrate acceptable reliability.

3. The Cube Comparison, Visualization of Views, Visualization of

Developments, Hidden Figures, and Visualization of Rotations Tests will

demonstrate criterion related validity evidence when compared to the gold

standard Mental Rotations Test.

4. The Cube Comparison Test and the Visualization of Views Test will

exhibit concurrent validity evidence as measures of spatial perception.

The Hidden Figures Test and the Visualization of Developments Test will

exhibit concurrent validity evidence as measures of spatial visualization.

The Visualization of Rotations Test and the Mental Rotations Test will

exhibit concurrent validity evidence as measures of mental rotation.

5. If the Cube Comparison, Visualization of Views, Visualization of

Developments, Hidden Figures, Visualization of Rotations, and Mental

Rotations Tests measure the trait of spatial ability, scores will reflect the

male-favored gender differences commonly found in the literature, and

will be positively related to the activities examined with the Spatial

Experience Questionnaire.

Research Question 3: To what extent is validity evidence provided for the use of the

Spatial Experience Questionnaire to measure spatial ability in Allied Medical students?

The major source of data for this study will come from a spatial experience questionnaire and four widely used spatial ability tests. To use these data to answer the research questions, the following assumptions are made:

1. The spatial tests used for the study are reasonable measures of the general

construct of spatial ability.

2. These spatial tests can differentiate types and levels of this ability.

3. The spatial experience questionnaire is a reasonable measure of types of

experiences in which students in this sample may have engaged.

4. Participants will quickly and accurately respond to as many items as possible

within the allotted time.

5. Participants will have adequate vision to complete the tests and questionnaire.

Technical Standards for the Allied Medical programs require normal or corrected

vision in order for students to function in didactic and clinical courses.

Organization of the Dissertation

This chapter introduced spatial ability, spatial ability tests, a spatial experience questionnaire, the various Allied Medical Professions, and the concept of validity. In addition, this chapter included the research questions and significance of the study.

Chapter Two will explore pertinent literature on the nature of spatial ability, the various models to explain its nature, spatial ability tests, spatial experience questionnaires, and pertinent studies in the medical field. Chapter Three discusses the population, sampling plan, the instruments, data collection procedure, and data analysis for this study. Chapter

Four will present the results of data analysis. Finally, Chapter Five will include a discussion of the results, describe limitations of the study, and suggest recommendations for further research.

Chapter 2: Review of the Pertinent Literature

Validity

Validity is a critical and fundamental issue when discussing any type of conclusions that are based on surveys or test instruments. Some authors describe validity and the process of validation as a process that helps to ensure that a measurement tool measures what it claims to measure, that it reflects the meaning of the concept that is under consideration (Babbie, 1995; Huck, 2004; Knapp & Mueller, 2010; Salkind, 2004).

Polgar and Thomas (2000) stated that validity is concerned with the accuracy of a measure, “in other words, the amount of measurement error” (p. 138). However it is important to note that many recent publications clarify this further by noting that validity is not a characteristic of the tool itself, but rather an indicator that the data and results are accurate. Anastasi and Urbina (1997) stated that the “validity of a test concerns what the test measures and how well it does so. It tells us what can be inferred from test scores”

(p.113). Dick and Hagerty (1971) are even more specific in stating that validity “gives some indication of how well a test measures a given area, under certain circumstances and with a given group” (p. 75). This definition is echoed in the Standards for

Educational and Psychological Testing (1999) which state that validity “refers to the degree to which evidence and theory support the interpretations of test scores entailed by 23 proposed uses of tests” (p. 9). The common thread on most of the current validity research is that it is not the instrument that is valid, but the uses and interpretations that must be put to the test.

Some authors describe various types of validity. These include content, construct, criterion, internal, external, face, ecological, curricular, differential, and others (Babbie,

1995; Carmines & Zeller, 1979; Dick & Hagerty, 1971; Polgar & Thomas, 2000; Salkind,

2004). The three the most commonly described types of validity are content, criterion, and construct.

Content validity refers to the extent to which a tool measures the domain of knowledge and skills of interest and the range of meanings associated with the concept of interest (Babbie, 1995; Bryant, 2000; Carmines & Zeller, 1979; Dick & Hagerty, 1971;

Huck, 2004; Knapp & Mueller, 2010; Polgar & Thomas, 2000; Salkind, 2004).

Validation of this sort is commonly used for tests of a particular skill and for achievement tests (Kane, 2006; Salkind, 2004). Evidence of content validity is commonly sought through the evaluation of expert judges who attempt to determine that items in the measurement tool reflect the universe of content being studied (Huck, 2004; Knapp &

Mueller, 2010; Salkind, 2004). Bryant (2000) noted that multivariate statistical methods such as principal components analysis, exploratory factor analysis, and confirmatory factor analysis can also be used to examine how well the tool measures the content domain. These types of analyses can provide information on the number of facets that are tapped by the test and whether any important content information is underrepresented

(Bryant, 2000; Kurpius & Stafford, 2006). Kurpius and Stafford (2006) noted that

24 comparison of the test items with specific job tasks could also provide evidence of content validity. Kane (2006) noted that this type of validation “works well if the relevant content domain has been defined with care, the tasks have been sampled in a way that makes them representative of the domain, the observations were made using procedures that would tend to control random and systematic errors, and the performances were evaluated appropriately” (p. 19). One fundamental limitation of content validation relates to the vagueness of certain concepts. If concepts are not described in enough detail and with sufficient exactness, it is nearly impossible to insure that a measurement tool adequately samples the intended domain (Carmines & Zeller,

1979). Messick (1989) stated that content validity provided evidence for how representative an instrument might be, but noted that this was a somewhat limited role in overall validation. Kane (2006) added that this type of validation evidence tends to be subjective, and while it might supply evidence for domain coverage, it does not involve test scores and so cannot justify conclusions related to the interpretation of these scores.

A second commonly described type of validity is criterion validity. A criterion is a standard, a rule, or a principle. Criterion validity examines test scores in relation to this standard. Evidence for this type of validity is commonly found by examining the extent of agreement between the test in question and a “gold standard” or benchmark validated measurement tool (Bryant, 2000; Knapp & Mueller, 2010; Salkind, 2004). This type of validity is further differentiated into concurrent and predictive validity. Concurrent validity correlates the tool being used to an external criterion or task at the same point in time to determine if the test measures current behavior. Predictive validation attempts to

25 correlate the tool with some future criterion or performance (Carmines & Zeller, 1979;

Kurpius & Stafford, 2006). This type of validity is commonly examined using correlation between the measure and the criterion variable. Correlation coefficients from these analyses are referred to as validity coefficients (Bryant, 2000; Carmines & Zeller,

1979). Carmines and Zeller (1979) noted that there may be many validity coefficients dependent upon the number of criteria for a particular trait. Criterion validity can also be examined using regression analysis and canonical correlation analysis (Bryant, 2000).

Kane (2006) stated that the major advantages to this type of validation include its objectivity and the relevance of the criterion to the proposed uses of tests and other measurement tools. He went on to note that the main limitation lies in the difficulty of finding a valid criterion (Kane, 2006; Kane, 2011).

The third type of validity that has commonly been described is construct validity.

Carmines and Zeller (1979) described this type of validity as being “concerned with the extent to which a particular measure relates to other measures consistent with theoretically derived hypotheses concerning the concepts (constructs) that are being measured” (p. 23). A construct is generally considered to be an explanation or a hypothesis about some type of behavior. Because these behaviors, attributes, or traits cannot be readily observed or measured their explanations tend to be based in theory.

Measurement tools must be compared to tools that reflect the theorized construct. The difficulty is in defining the construct sufficiently to determine that the test measures only the relevant construct and not a related trait or attribute. Evaluation of construct validity generally involves establishing evidence for convergent or discriminant (sometimes

26 called divergent) validity. Convergent validity provides evidence that tools meant to measure the same thing are related. That is, all tools measuring the same construct should correlate highly (Bryant, 2000; Huck, 2004). Discriminant validity verifies that tools that should have no relationship (that measure different constructs) are not related.

The first step in establishing construct validity is clearly formulating a definition of the underlying construct (Bryant, 2000; Carmines & Zeller, 1979). This involves “carefully specifying the necessary components or key ingredients that constitute the construct and what distinguishes it from related but separate constructs” (Bryant, 2000, p. 112;

Carmines & Zeller, 1979). Convergent and discriminant validation may be reported in terms of correlations between instruments. Factor analysis is another tool which helps to establish evidence for construct validity (Carmines & Zeller, 1979; Knapp & Mueller,

2010).

Kane (2006) reported that authors such as Cronbach had called for an overall evaluation of validity with multiple sources of evidence and that construct validation was

“widely accepted as the general approach to validity” (p. 21) in the early 1980s. In the mid to late 1980s, Messick described construct validation as a unifying framework for validity (Messick, 1989). Kane (2006) noted that there were three positive effects for using the construct validation as a unified framework for validity: 1) this model focused on issues related to interpretations and uses of test scores rather than simply correlations with criteria, 2) the role for, and need to check assumptions in score interpretations, and

3) allowance for alternative interpretations for tests and test uses.

Unified Theory of Validity

The unified theory of validity is a broad conceptual framework. Anastasi and

Urbina (1997) clarified that “almost any information gathered in the process of developing or using a test is relevant to its validity” (p. 138). Because so many types of evidence can be presented in the validation process, it can seem like an endless process

(Kane, 2006). For that reason, Kane (2006) characterized the unified theory of validation as “quite appealing as a conceptual framework for validity” but stated that “it didn’t provide clear guidance for validation of a test-score interpretation or use” (p. 21). He also stated that this method of validation tended to be “very open-ended”, and that “it is not clear where to begin or how to gauge progress” (Kane, 2006, p. 21; Kane, 2011, p. 8).

The basic questions regarding validity are: what is being claimed and are these claims warranted, given the evidence (Kane, 2011, p. 4). An argument-based approach to validity can be used to attempt to answer these questions. This approach is used to examine the interpretations and uses of test score by “generating a coherent analysis of all of the evidence for and against the proposed interpretation or use, and to the extent possible, the evidence relevant to plausible alternative interpretations and decision procedures” (Kane, 2006, p. 22). Kane (2006) went on to note that the main advantage in this approach “is the guidance it provides in allocating research effort and in gauging progress in the validation effort” (p. 23).

Validation has two major components in the argument-based approach: the interpretive arguments and the validity arguments (Kane, 2006; Kane, 2011). The interpretive arguments develop a network of assumptions leading from the interpretation of test performance or scores to the decisions based on these performances or scores.

Validation relies on the support provided by the assumptions and the plausibility of the interpretations. This type of validation “specifies the reasoning involved in getting from the test results to the conclusions and decisions based on these results” (Kane, 2006, p.

25). The validity argument is then used to evaluate the interpretive argument; to see if it makes sense, is plausible, and to determine if it is reasonable (Kane, 2006; Kane, 2011).

The interpretive argument commonly involves inferences related to scoring, generalizability, extrapolation to broader domains, and decision-making. Kane (2011) declared “Each inference in the interpretive argument extends the interpretation or adds a decision” (p. 8). The scoring inference generally claims that the “scoring rule is reasonable and has been applied appropriately and consistently” (Kane, 2011, p. 8). A generalization inference makes the argument that observed scores can be taken as an indication of performance over a broader domain of task performance. To support this inference, reliability and/or generalizability evidence is needed. Scores can be referenced to norms for other measures, groups, benchmark performances, etc. Another common inference relates to extrapolation of scores to a broader domain. These types of inferences require criterion related analyses. There are many other types of inferences that can be used. The key is that the inferences and assumptions provide the framework for validation.

Kane (2011) held that interpretive arguments are informal, presumptive arguments and three characteristics distinguish these arguments from more formal arguments:

1. Their assumptions are subject to challenge, and they can be evaluated in terms

of how well they stand up to such challenges.

2. Their assumptions and conclusions are tentative, or probable, rather than

certain.

3. They are defeasible in the sense that they can be overturned in a particular case

even if the argument is generally sound (Kane, 2011, p. 11)

Presumptive arguments favor conclusions, but are never certain; they just offer strong support for the claims that are being made. Kane (2006, 2011) cites Toulmin’s (1958) framework for analyzing informal arguments. According to this framework, each inference starts from a datum and ends with a claim. A warrant is used to justify the inference so that the claim can be reasonably inferred from the datum. Warrants are if- then rules and require justification or supportive evidence called backing. Kane (2011) stated “The interpretive argument specifies the inferences involved in getting from the observed performances to the conclusion to be drawn and the decisions to be made based on test scores. It would include a network or chain of inferences. The validity argument would provide a critical appraisal of the coherence of the interpretive argument and an evaluation of the warrants and their backing for the inferences in the interpretive argument” (Kane, 2011, p. 12).

The 1999 Standards for Educational and Psychological Testing also described to process of validation as a process of developing a “sound validity argument to support the intended interpretation of test scores and their relevance to the proposed use” (p.9). This document advocates the development of a set of propositions supporting any proposed interpretation of a testing process. Once developed, these propositions can be evaluated by things such as empirical studies and literature review in order to establish validity.

Twenty-four Standards offer guidance in developing validity evidence for proposed uses and interpretations of tests (American Educational Research Association,

1999). Potential sources of evidence in the validation process include an examination of the content domain covered by the test, establishment of reliability and generalizability, determination of relationships to criterion measures, and an investigation as to the consequences of the decisions resulting from score interpretations. These types of processes closely mirror the argument-based approach explicated by Kane (2006).

All available information is therefore helpful in establishing validity evidence for a test or measurement tool. The Standards for Educational and Psychological Testing

(1999) stated “Ultimately, the validity of an intended interpretation of test scores relies on all the available evidence relevant to the technical quality of a testing system. This includes evidence of careful test construction; adequate score reliability; appropriate test administration and scoring; accurate score scaling, equating, and standard setting; and careful attention to fairness for all examinees…” (p. 17). In order to begin the validation process proposed by this study, an examination of the relevant construct is essential. The

31 following sections examine spatial ability, in an attempt to accurately identify the relevant constructs associated with this trait.

The History of Research Related to Spatial Ability

Any historical discussion of spatial ability must begin with the studies of intellect conducted by Charles Spearman. In the early 1900s Spearman conducted several experiments with school-aged children in an attempt to understand human intelligence.

Through his pioneering work with factor analysis, he theorized that all tests of mental ability measured a general ability factor (g factor) and at least one specific factor (s1, s2, s3…). These specific factors were uncorrelated with the general factor, and may or may not be correlated with each other. When specific factors were correlated, abilities measured by scores from a test were thought to be related to a group factor (Jensen, 1998;

Spearman, 1904; Spearman, 1938). The g factor represented that which a test had in common with all other tests of ability; the s factors represented specific abilities (e.g. spatial) which were assumed to be peculiar to each test (Eliot & Smith, 1983). Over the past 100 years some authors have agreed and some have disagreed with Spearman’s research and/or methods, (Smith, 1964), but all spatial ability research has in some manner built on his framework in the two factor theory of intelligence.

During the early decades of the twentieth century researchers in psychology and education had a profound interest in understanding intelligence (Spearman, 1904;

Thurstone, 1924). Was mental ability a single concept, or were there multiple types of

32 intelligences? How did children learn? Were there ways (e.g., tests) which could predict academic success? Was verbal reasoning synonymous with intelligence? How should those with poor verbal skills be tested? Non-verbal tests were being developed during this period, but the question remained: what were these tests measuring (El Koussy,

1935; McFarlane, 1925; Spearman, 1904; Spearman, 1938; Spearman, 1946)?

According to Smith (1964), the original impetus to develop mental tests arose from a perceived need to improve methods of predicting scholastic success. In addition to the work of Spearman, in the first decade of the 1900s Binet was developing mental tests which were designed to predict academic success. These tests were rooted in reading and writing, and these verbal skills were found to be the most successful predictors of school achievement. The assumption that verbal types of questions are able to measure intelligence, lead to these types of tests being called “intelligence tests”

(Smith, 1964). With the increased use of these verbal tests, some complained that the scales were unsatisfactory for testing students who had difficulty with language skills, and this gave rise to the development of non-language or performance types of tests

(Eliot & Smith, 1983). The non-language tests included activities such as jigsaw-like form boards, wooden construction activities, dress-pattern cutting, pegboards, etc.

(McFarlane, 1925; Smith, 1964). Non-language tests of intelligence were slow to be accepted since all of these tests were initially devised to predict academic success and academic success was closely associated with the ability to read and write (Eliot &

Smith, 1983), and because administering the tests was done individually, so it was a slow and cumbersome process (Smith, 1964).

In 1918, the United States Army initiated large-scale testing for both verbal skills

(Alpha Test) and non-verbal skills (Beta Test). The Alpha Test was given to educated or literate recruits, while the Beta Test was used for the uneducated or those who had difficulty with language. The Beta Tests were used to assess practical or mechanical ability, and according to Smith (1964), included paper versions of practical tests like form boards and maze tracing as well as peg-board, wire bending, tapping, and manipulation exercises. This was the first non-verbal battery of tests to be given to a large number of subjects, and included some of the first paper-and-pencil tests which we now think of as spatial in nature (Eliot & Smith, 1983; Smith, 1964).

During the 1920s, the literature on mechanical and practical ability tests seemed to point to a spatial factor of intelligence that was independent of g. These types of tests were thought to be the original spatial tests (Carter, LaRussa, & Bodner, 1987; Eliot &

Smith, 1983; Zimowski & Wothke, 1988). One of the first studies to demonstrate a spatial factor independent of g was completed by McFarlane in 1925 (Eliot & Smith,

1983; McGee, 1979; Smith, 1964). In an investigation of “practical” ability using construction type tests and puzzle boxes McFarlane (1925) found some evidence of the presence of a group factor additional to g with her sample of boys but not with girls. The group factor she isolated was found in boys to a higher degree than girls, was independent from general intelligence, and she suggested that those who have it can judge better about concrete spatial situations (McFarlane, 1925).

During the late 1920s, some researchers concentrated on developing practical and/or mechanical tests. The authors of some of these tests claimed that they were highly

34 successful in selecting prospective mechanical engineers and measuring other types of mechanical abilities such as those seen in shop classes (Smith, 1964). Unfortunately, early forms of these tests consisted of mechanical models which were very elaborate, expensive and time consuming to administer.

Other evidence of a unique spatial factor, separate from general intelligence, was emerging in studies conducted in the late 1920s and 1930s. Spatial factors were beginning to be studied in their own right by researchers such as Kelley, Alexander, El

Koussy, and Smith (Lohman, 1989; Smith, 1964). Factor studies of elementary and middle school children suggested evidence of a spatial factor that could be separated into two parts which were designated: ε—ability involving the sensing and retention of geometric forms and θ—a facility in the mental manipulation of spatial relationships

(Kelley, 1928). El Koussy (1935) administered a large battery of tests covering a wide range of abilities to groups of children, and compared them with reference tests for g. He concluded that some spatial tests involved a group factor over and above their g-content.

This group factor, called the k-factor, “receives a ready psychological explanation in terms of visual imagery” (El Koussy, 1935, p. 65). From subject feedback he concluded

“the explanation of the k-factor consists in the ability to obtain and the facility to utilize visual, spatial imagery” (El Koussy, 1935, p. 65). In the mid 1930s, Smith (1964) did research similar to El Koussy. He found evidence for the presence of a spatial group factor (similar to El Koussy). This group factor was present in tests that require an ability to form and retain an exact impression of shape or pattern. His battery of tests showed significant gender differences with boys doing better than girls. In addition, he found

35 significant correlations for test scores with art, geometry, and engineering drawing but not with handwork. He concluded that ability measured by these types of tests might be useful in certain occupations and an improved form of the test might be used as a diagnostic test of ability for the above occupations and/or school subjects (Smith, 1964).

Thurstone disagreed with Spearman’s Two Factor theory and reported that human intelligence was composed of many independent or primary factors rather than one general ability factor (Eliot & Smith, 1983; Smith, 1964; Thurstone, 1947). In the late

1930s, Thurstone evaluated results from 56 psychological tests using factor analysis. He identified seven primary ability factors, named for the “type of thinking that is involved in doing the task” (p. 1) which included: verbal (V), number (N), space (S), memory (M), and perception (P) (Thurstone, 1938). Eliot and Smith (1983) reported that Thurstone defined his space factor as “requiring a facility in spatial or visual imagery” (p. 3) where subjects taking tests needed to turn, rotate, or transform images mentally.

During the 1940s and 1950s, authors continued the debate over intellectual ability, how spatial factors differed from each other, and developed new measures of spatial ability (Eliot & Smith, 1983). Using various statistical techniques, they tried to solve the question of g versus multiple ability factors. Also during this period, many of the spatial tests in use today were developed (Zimowski & Wothke, 1988). Large scale ability testing was again undertaken by the military in order to classify personnel for pilot training or aircraft maintenance. Many new tests were developed for this project, and the battery was administered to thousands of military personnel. Factor analysis of the test results provided strong evidence for the existence of several spatial factors (Eliot &

Smith, 1983; Smith, 1964). Guilford and Lacey (1947) found that one cluster of tests seemed to measure spatial relations which they described as requiring the subject to determine the relationships between different spatially-arranged stimuli and responses, and the comprehension of the arrangement of elements within a visual stimulus. They also found a second cluster of tests that seemed to pertain to visualization which they describe as the ability to imagine the rotation of depicted objects, the folding and unfolding of flat patterns, and the relative changes of position of objects in space.

During the late 1940s and early 1950s, work continued in attempting to identify the nature of spatial intelligence. Thurstone developed tests for his Primary Abilities and continued testing large groups of adolescents and adults. Smith (1964) reported that in a reanalysis of his primary ability factors, Thurstone found three factors having to do with visual orientation in space (his space factor) which he called S1, S2, and S3. S1 seemed to be the ability to recognize the identity of an object when it is seen from different angles or as the ability to visualize a rigid configuration when it is moved into different positions, S2 appeared to be the ability to imagine the movement or internal displacement among the parts of a configuration, and S3 appeared to be the ability to think about those spatial relations in which the body orientation of the observer is an essential part of the problem.

Fruchter (1954) reported that during this period Burt (1949) had distinguished two sub-factors of practical ability: spatial and mechanical. Burt defined his space sub-factor as the ability to perceive, interpret, or mentally rearrange objects as spatially related. He said that at least two spatial factors are needed, a factor for static spatial relations and a

37 factor for kinetic spatial relations; he further subdivided the static sub-factor into two- and three-dimensional abilities (Fruchter, 1954).

During this period, several authors reanalyzed the Army Air Force Data and found evidence for at least three spatial factors (Eliot, 1980; Smith, 1964). Eliot and

Smith (1983) reported that French (1951) isolated three spatial factors: space or spatial factor, spatial orientation, and spatial visualization. Zimmerman (1954), using increasingly difficult versions of the Army Air force tests, was reported to have demonstrated that increasing the difficulty of items on the Army Air Force experimental test could be made to emphasize in succession a perceptual speed, a space, and a visualization factor, and claimed that the ability to visualize relationships required more intellectual effort than the ability to carry out tasks requiring spatial orientation alone

(Eliot & Smith, 1983; Smith, 1964).

During the 1940s and 1950s, Eliot and Smith (1983) reported that spatial ability terminology had become very confusing. Spatial factors were referred to in a number of different ways by various researchers, and sometimes the same term was used to identify entirely different abilities by different authors. Three spatial factors seemed to emerge from an analysis of the literature at that time. Eliot and Smith (1983) explained these factors and their relationships with other terms of the day as follows:

Spatial relations and orientation (SR-O) seemed to be a composite of Thurstone’s

S1 and S2 and a composite of French’s Space and Spatial Orientation. It is the

ability to comprehend the nature of an arrangement of elements within a visual

stimulus pattern primarily with respect to the examinee’s body as the frame of

reference.

Visualization (Vz) was found in results from tests that required mental

manipulation.

Kinestetic imagery (K) appeared to be the same as Thurstone’s K-factor, and

closely linked to El Koussy’s k.

From the 1960s and onward, research on spatial ability exploded. Some authors have conducted investigations attempting to further explain the complex nature of spatial ability, (Eliot, 2002; Linn & Petersen, 1985; Lohman, 1988; McGee, 1979), while others have attempted to create models that explain spatial ability (D'Costa, 2005; Guilford,

1967; Wattanawaha & Clements, 1982). One of the largest areas of research in the past

50 years has focused on individual differences in spatial ability. This research will be summarized in later sections of this chapter.

What is Spatial Ability?

From the factor studies regarding the nature of human intelligence described above, it has been found that one of the most consistently identified factors is spatial ability. This mental ability is a complex concept which researchers have struggled to define, describe, characterize, and assess for nearly 100 years. Understanding the fundamentals of this mental ability is complicated, and it is rendered even more difficult because authors aren’t sure whether it is a single ability or a mixture of various abilities. 39

Many of the definitions of spatial ability are based on the nature of the tests used in factor analysis studies, which may or may not relate to real-world abilities. To begin to understand spatial ability, some of the prevailing definitions and descriptions of this trait are discussed below.

In general, spatial ability has been defined as the cognitive skill or ability to reason or mentally represent spatial relationships, visual and nonvisual, and to anticipate the course and outcome of mental transformations applied to those relations (Berg,

Hertzog, & Hunt, 1982; Michaelides, 2003; Reio, Czarnolewski, & Eliot, 2004; Rilea,

2008). It has been described as entailing “visualization and mental transformation of two- and three-dimensional images” (Jardine & Martin, 1984, p. 345), and as the ability to generate, represent, retain, recall, and transform abstract visual symbolic images and information (Cherney, 2008; Kyllonen, Lohman, & Snow, 1984; Linn & Petersen, 1985;

Lohman, 1996). However, Guay (1980) argued that it is the mental manipulation involved, and not the perception or retention, which enables a task to measure spatial ability (p.5). Spatial ability has also been defined in terms factor analysis results. For example, groups of tests that load on a particular factor may all require one to mentally manipulate figures or images (Michaelides, 2003; Zimowski & Wothke, 1988). Other terms used for general spatial ability include spatial intelligence, visuospatial ability, and the Space factor.

Eliot (2000) described spatial intelligence as entailing “a very general capacity for seeing patterns and connections” and as “the capacity to put the relationships of the world together in one’s head such that the distance and the directional positioning of things

40 becomes part of an interconnected system of knowledge” (p.1). He noted that this ability is so pervasive that it is difficult to measure. It is involved in symbolic processing, it may be involved with body movement and orientation, it may operate on many levels at once, and it may interact with other cognitive functions to solve everyday problems (Eliot,

2000; Eliot, 2002). In their 1985 meta-analysis, Linn and Petersen noted that spatial ability “is an important component of intellectual ability, yet its nature remains to be clarified. Activities as disparate as perception of horizontality, mental rotation of objects, and location of simple figures within complex figures have all been referred to as measures of spatial ability” (p. 1479).

Guay and McDaniel (1977) divided spatial ability into low and high ability levels.

They described low level spatial abilities as “requiring the visualization of two- dimensional configurations, but no mental transformations”, and high level spatial abilities as being “characterized as requiring the visualization of three-dimensional configurations, and the mental manipulation of these visual images” (p. 211).

Based on factor analytic and other types of studies, authors have differentiated various subtypes of spatial ability. Two of the most commonly cited types of spatial ability are spatial visualization and spatial orientation (Carter, LaRussa, & Bodner, 1987;

Guilford & Lacey, 1947; Jardine & Martin, 1984; Kaufman, 2007; McGee, 1979;

Newcombe, Bandura, & Taylor, 1983). Visualization, visuospatial ability, and spatial visualization are occasionally discussed as separate entities, however in much of the literature these terms are used interchangeably. Other subtypes or facets of spatial ability discussed in the literature include spatial relations, spatial perception, closure speed,

41 closure flexibility, mental rotation, and spatial scanning, just to name a few (Guilford,

Fruchter, & Zimmerman, 1952; Linn & Petersen, 1985; Lohman, 1988; Lohman, 1989;

Lohman, 1996; Voyer, Voyer, & Bryden, 1995).

At its simplest, spatial visualization involves the ability to mentally manipulate information of a spatial nature. This mental manipulation may be in the form of transformations, rotations, reflections, and/or inversions (Bishop, 1980; Bock &

Kolakowski, 1973; Ekstrom, French, & Harman, 1976; Guilford, Fruchter, &

Zimmerman, 1952; Guilford & Lacey, 1947; Lord, 1990; McGee, 1976). It is generally agreed that the information is complex, or the mental processes involved are difficult or multifaceted. Patterns may need to be rearranged, or internal configurations of the visualized object may need to be mentally altered (Linn & Petersen, 1985; Lohman,

1996; Martin-Dorta, Saorin, & Contero, 2008; McGee, 1979; Rilea, 2008; Voyer, Voyer,

& Bryden, 1995). Stimuli in tests used to measure this factor may be two-dimensional, but are more generally thought to be three dimensional (Martin-Dorta, Saorin, & Contero,

2008; McGee, 1979). Guay (1980) summed up the uniqueness of spatial visualization by saying that mental manipulation is the critical component that sets this factor apart from other spatial abilities. Some researchers differentiate visualization from other types of spatial ability because it seems to require complicated, multistep processing of spatial information which can be kept in mind even when there are distractions (Ben-Chaim,

Lappan, & Houang, 1988; Hassler, Birbaumer, & Feil, 1985; Linn & Petersen, 1985;

Rilea, 2008; Voyer, Voyer, & Bryden, 1995). Spatial visualization is commonly associated with tests that require folding or unfolding of patterns, displacement or

42 restructuring of internal components of a figure, and serial operations to complete a task

(Ekstrom, French, & Harman, 1976; Guilford & Lacey, 1947; Lohman, 1988; Martin-

Dorta, Saorin, & Contero, 2008; McGee, 1979).

Another component of spatial ability identified by multiple authors is spatial orientation. McGee (1979) summarized works from Thurstone, French, Guildford and

Lacey, and Ekstrom to develop the following definition for spatial orientation:

…the comprehension of the arrangement of elements within a visual stimulus

pattern and the aptitude to remain unconfused by the changing orientation in

which a spatial configuration may be presented, and the ability to determine

spatial orientation with respect to one’s body (p. 897).

Researchers tend to agree that what differentiates spatial orientation from spatial visualization is the concept that relationships are viewed and/or manipulated from the perspective of one’s own body (Bishop, 1980; Ekstrom, French, & Harman, 1976;

Guilford, 1967; Lohman, 1988; McGee, 1979). In addition, spatial orientation tends to involve moving or mentally viewing a configuration as a whole, or determining how an object or figure will appear from a new or different perspective (Ekstrom, French, &

Harman, 1976; Hassler, Birbaumer, & Feil, 1985; Lohman, 1988; Lord, 1990). Linn &

Petersen (1985) described a similar ability wherein subjects must determine spatial relationships with respect to the orientation of their own bodies, in spite of distracting information, and called it spatial perception (p. 1482). They found that this ability was also factored out in tests which required disembedding activities or the ability to overcome distracting cues.

One of the most widely studied aspects of spatial ability is the facility to mentally rotate an object. Although some authors see this as an embedded aspect of spatial visualization, Linn and Petersen (1985) viewed mental rotation as a unique type of spatial ability. Their meta-analysis of gender differences in spatial ability led them, and consequently many other researchers, to conclude that mental rotation involves the ability to retain a two- or three-dimensional object in the mind, mentally rotate it quickly and accurately in space, and then compare it to another object to determine similarity or differences (De Lisi & Cammarano, 1996; Guillot, Champely, Batier, Thiriet, & Collet,

2007; Heil & Jansen-Osmann, 2008; Linn & Petersen, 1985; Moe, Meneghetti, &

Cadinu, 2009; Monahan, Harke, & Shelley, 2008; Rilea, 2008). Tests that measure this ability have consistently demonstrated the largest gender differences, especially the mental rotation tests of Shepard and Metzler (1971), and Vandenburg and Kuse (1978).

These consistent gender differences are one of the things that differentiate this ability from spatial visualization and spatial orientation (Linn & Petersen, 1985; Voyer, Voyer,

& Bryden, 1995).

Although less commonly discussed in the spatial literature, other sub-factors of this ability have been described. Closure speed (sometimes called Speed of Closure) is an ability to quickly identify ambiguous visual stimuli or visual patterns even if distorted or obscured in some way. It involves the ability to quickly identify an incomplete or distorted picture when the subject does not know what the pattern is in advance (Ekstrom,

French, & Harman, 1976; Lohman, 1988; Lohman, 1996). Closure flexibility (or

Flexibility of Closure) is an ability to quickly identify visual patterns even if distorted or

44 obscured in some way when the subject does know what the pattern is in advance

(Lohman, 1988; Lohman, 1996). It is also described as the ability to hold a given visual percept or configuration in mind so as to disembed it from other well defined perceptual material (Ekstrom, French, & Harman, 1976, p. 19). Perceptual speed involves finding or accurately comparing figures and symbols, or quickly matching visual stimuli (Ekstrom,

French, & Harman, 1976; Lohman, 1988; Lohman, 1996). Perceptual speed has been called cognition of visual figural units or evaluation of figural units by Guilford in his

Structure of Intellect model (Guilford, 1967), speed of perception by Thurstone, and

Gestalt perception by French (Lohman, 1988; Lohman, 1996). Serial Integration is described as an ability to integrate temporally spaced visual stimuli (Lohman, 1988).

Spatial scanning (sometimes called Planning Speed) involves activities like scanning for a correct answer prior to marking a test item (Lohman, 1988), or quickly exploring wide or complicated visual fields (Ekstrom, French, & Harman, 1976). It has been described when maze or path-finding tests are included in spatial batteries (Lohman, 1988).

As can be seen for the above summary of research findings, spatial ability is a highly complex concept. Researchers still do not completely agree on the nature of this ability. While some authors conduct studies as if spatial ability is it a solitary trait, others view it as a complex set of multiple abilities. Definitions are also varied, and frequently conflict with each other. In some cases spatial factors are only defined in terms of the tests that load on a particular factor (Guilford, 1967; Guilford, Fruchter, & Zimmerman,

1952; Guilford & Lacey, 1947).

Much of the current literature on spatial ability is concerned with individual differences in this type of intelligence. This literature can roughly be grouped into biological causes and environmental causes of individual differences in ability. Relevant studies in these areas are summarized below.

Individual Differences in Spatial Ability

Research has shown that individuals vary in their ability to visualize mental concepts and to manipulate spatial relationships. The reason for these differences is not clearly understood, and comprehending the underlying causes of these differences has been a focus of hundreds of research studies. One intriguing question is: Are we born with a certain spatial ability, or can we develop and refine it? Biologic factors have been proposed by numerous authors as the cause for spatial ability differences. Gender, chronological age, brain organization, processing strategy employed, the effects of hormones, genetic influences, and personality characteristics have all been proposed as biologic reasons for spatial ability differences. Another school of thought relates to environmental causes for differences in spatial ability. The ways children are raised, the toys they play with, and the activities they engage in may all be involved in developing a sense of spatial awareness. The types of tests and the mechanisms for testing have also been implicated in determining whether differences are seen in spatial abilities. The following sections will discuss some of the potential biological, environmental, and mechanical causes for variations in spatial ability.

Biologic Factors Related to Individual Differences in Spatial Ability

One biologic factor, gender, has been widely researched in studies of individual differences in spatial ability. Gender differences in certain intellectual abilities have been established, and are widely accepted for verbal and qualitative reasoning (Maccoby &

Jacklin, 1974). There is also a widely held belief that men tend to perform better than women on tests of spatial ability (Guay, 1978; Hyde, Geiringer, & Yen, 1975; McGee,

1979). Researchers have been trying to understand this phenomenon since the 1930s.

In 1974, Maccoby and Jacklin performed an extensive review of the available literature on sex differences in intelligence, achievement, and social behavior. Sex differences in spatial ability favoring males were clearly established. In an extensive review of the literature, McGee (1979) stated that male superiority on spatial visualization and orientation tasks is among the most persistent of individual differences in all of the abilities literature (p. 895). Hyde (1981) reanalyzed the studies in the

Maccoby and Jacklin research and found that the gender differences were consistent and replicable, although the differences were not large. Two other meta-analyses corroborated the findings on gender differences in spatial ability, but found that the differences varied by the groups of tests used and the ability measured (Linn & Petersen,

1985; Voyer, Voyer, & Bryden, 1995).

Linn and Petersen (1985) conducted a meta-analysis of spatial ability literature from 1974 through 1982. Their goal was to further clarify the magnitude, nature, and age

47 of first occurrence of gender differences. Their study was informed by four research perspectives: comparisons of different populations, factor studies comparing different spatial tasks, identification of the cognitive processes used to solve spatial tasks, and identification of the various strategies used to solve spatial tasks. Their analyses of 172 effect sizes enabled them to name and describe three categories of spatial ability: spatial perception, mental rotation, and spatial visualization.

Spatial perception tasks involve determining spatial relationships with respect to one’s own body orientation in spite of distraction. Tests that require the examinee to determine horizontality such as the Rod and Frame Test and the Water Level Test are examples of measures for this ability. Gender effect sizes favoring males for this category of spatial tasks were significant for those over 18 years of age and amounted to about two thirds of a standard deviation.

The second ability category described by Linn and Petersen was spatial visualization, which they noted is an ability commonly associated with performing complicated multistep spatial tasks. Common tests associated with this ability include paper folding, surface development, and hidden figures tasks. These tasks generally tend to require more analytical cognitive processing strategies. Gender differences on tests of spatial visualization were homogenous over the life span, but small, with an average effect size of .13 which failed to reach significance. They concluded that this type of spatial ability was equally difficult for both males and females.

The third category of spatial ability described by Linn and Petersen was mental rotation. In earlier spatial ability studies mental rotation was considered an aspect of

48 spatial visualization. However, research concerned with the Vandenberg and Kuse

(1978) Mental Rotations Test had shown it to have a low relationship to other factors in test batteries and, unlike other tests of spatial visualization, to have low correlations with verbal tests. Linn and Petersen suggest that this type of test may identify a spatial ability that is separate from visualization.

Tests that fall into this category include those mental rotation tasks developed by

Shepard and Metzler (1971) and Vandenberg and Kuse (1978). Researchers have claimed that these types of tasks involve holistic, or Gestalt types of mental processing to successfully solve (Guay, 1978; McGee, 1979; Shepard & Metzler, 1971), although this is still questioned by others (Just & Carpenter, 1985) because of the complexity of the items and the speeded nature of mental rotation tests. For mental rotation tasks analyzed in the Linn and Petersen (1985) study, sex differences favoring males were seen as soon as mental rotation could be measured in subjects, were homogenous over all of the ages included in the study, and were largest in studies which had used the Vandenberg and

Kuse test. In fact, the overall estimator for effect size for gender differences on this test was .94, almost an entire standard deviation (Linn & Petersen, 1985).

Voyer, Voyer, and Bryden (1995) also sought to determine the magnitude of sex differences in spatial ability. Using meta-analysis techniques, they examined studies in the spatial literature from 1974 through 1993 which yielded a total of 286 effect sizes. In attempting to categorize spatial abilities, their results replicated the work of Linn and

Petersen (1985) and the same three categories were used: spatial perception, mental rotation, and spatial visualization. Results of the overall analysis of the 286 studies

49 revealed an effect size of .37 for gender which demonstrated that “sex differences in spatial abilities favoring males are highly significant” (p. 253). The sex difference in spatial perception was found to have an overall effect size of .44, with a small and gradual increase between the ages of 13 and adulthood. Mental rotation tasks again showed the highest overall effect of .56, but this study found that the magnitude of gender differences increased from adolescence to adulthood. Finally, small gender differences were found in spatial visualization, increasing from .02 at age 13 to .23 for adults with an average effect size of .13.

In addition to the above large studies, various other authors have reported gender differences in spatial abilities favoring males. Guay (1978) found that males performed significantly better than females on tests designed to measure surface development, object rotation, and coordination of viewpoint tasks. Using the Heinrich Spatial

Visualization Test, Chen (1995) found significant gender differences in spatial ability with male Taiwanese college students outperforming female students. Dunn and Eliot

(1999) found significant correlations between gender and performance on the CTY spatial battery which included seven subtests. Studies using various versions of the

Mental Rotations and other tests have demonstrated fairly large and reliable male superiority on test scores, approaching a Cohen’s d value of 1.5 (Castelli, Corazzini, &

Geminiani, 2008; Colom, Contreras, Arend, Leal, & Santacreu, 2004; Geiser, Lehmann,

& Eid, 2008; Johnson & Bouchard, 2007; Kaufman, 2007; Keith, Reynolds, Patel, &

Ridley, 2008; Parsons, et al., 2004; Peters, Laeng, Latham, Jackson, Zaiyouna, &

Richardson, 1995; Peters, Lehmann, Takahira, Takeuchi, & Jordan, 2006). Although the

50 age at which sex differences in spatial ability emerges is still questionable, it has been claimed that male superiority in spatial tasks can be seen as early as three to four months of age (Moore & Johnson, 2008; Quinn & Liben, 2008).

Male superiority in spatial ability is not always supported by research. Olson and

Eliot (1986) found no correlation between gender and the composite scores on the Spatial

Dimensionality Test (a group of 6 spatial ability tests). Michaelides (2003) found no significant gender differences in children performing a block rotation task. It has also been reported that gender differences on some tests disappear when subjects are given instructions that indicate the task is a measure of empathy or general intellect (Caplan,

MacPherson, & Tobin, 1985; Michaelides, 2003), or when tests are scored in non- standard ways (Goldstein, Haldane, & Mitchell, 1990; Stumpf, 1993). Some claim that gender differences are disappearing altogether (Feingold, 1988; Stumpf, 1989), but these claims are in dispute (Halpern, 1989; Hedges & Nowell, 1995).

Some studies of individual differences in spatial ability have advocated that brain function and organization is the biologic factor responsible. It is believed that male and female brains perform neural tasks differently. Studies of the brains, utilizing functional magnetic resonance imaging (fMRI), have demonstrated that different areas of the brain, mainly the parietal lobe, are activated when performing either a mental rotation or an orientation type of spatial task (Keehner, Guerin, Miller, Turk, & Hegarty, 2006;

Wantzel, Hamsta, Anastakis, Matsumoto, & Cusimano, 2002; Zacks, 2008). Other studies have focused on differential organization of the brain’s hemispheres, termed lateralization. Male brains tend to be more asymmetrically organized and it is believed

51 that language processing is predominant in the left hemisphere while perception and non- verbal processes like spatial ability are mainly processed in the right hemisphere which may partially explain gender differences in spatial ability (Levy, 1976; Newcombe,

Dubas, & Baenninger, 1989; Rilea, 2008; Rilea, Roskos-Ewoldsen, & Boles, 2004;

Zacks, 2008).

A related avenue of research has examined handedness in relation to individual differences in spatial ability. Studies of the relationship between handedness and spatial ability are conflicting. If spatial processing in centered in the right hemisphere and asymmetrical hemispheric processing improves spatial ability as laterality theories predict, then it would be expected that left-handed females would have the poorest spatial performance while left-handed males should have the best performance on spatial tasks

(McGee, 1976). Right-handed subjects were found to perform better than left-handed subjects on spatial tasks by some researchers, but not on all tasks or in all situations

(Guay, 1978; Levy, 1976; McGee, 1976; Yen, 1975). No significant effects for handedness were reported by various authors (Ecuyer-Dab, Tremblay, Joanette, &

Passini, 2004; Li, Zhu, & Nuttall, 2003; Peters, Laeng, Latham, Jackson, Zaiyouna, &

Richardson, 1995); however, Reio, Czarnolewski, and Eliot (2004) found that three- dimensional rotation/visualization and maze tracing tasks showed a small but significant relationship with tendency to left-handedness.

Another potential biologic source of variance in spatial ability scores may be related to the influence of sex hormones. If differences in spatial ability emerge early in life, prenatal hormones may play a role by having some effect on brain organization and

52 function (Delgado & Prieto, 1996; Linn & Petersen, 1985; Moe, Meneghetti, & Cadinu,

2009; Moe & Pazzaglia, 2006; Moore & Johnson, 2008; Quinn & Liben, 2008). Moore

(2008) cited studies in which positive associations are found between spatial ability in seven to twelve year olds and their androgen levels during gestation, postulating that higher androgen levels in utero influence the development and organization of the nervous system which in turn contributes to spatial ability.

On the other hand, sex hormone levels may influence brain organization as a child goes through puberty, and if this is so, ability differences would emerge in adolescence.

Since males typically outperform females on tests of spatial ability, and since males are typically later in maturing than females, it has been suggested that there is a relationship between the brain’s exposure to sex hormones and the neural processing needed for spatial tasks (Linn & Petersen, 1985; McGee, 1979; Sanders & Soares, 1986). Studies of spatial ability in relation to the timing of puberty have found that both males and females who mature later tend to have better scores on measures of mental rotation, but differences tend to be relatively small (McGee, 1979; Newcombe & Bandura, 1983;

Sanders & Soares, 1986).

Because men tend to perform better on spatial tests, some believe there is a genetic cause for women’s poorer performance on these measures (Hyde, Geiringer, &

Yen, 1975). This type of biologic cause could explain differences that emerge in young children (Linn & Petersen, 1985). Traits related to the transmission of a gene on the X- chromosome are said to be X-linked; if the trait is recessive, more males than females would be affected (Goldstein, Haldane, & Mitchell, 1990; McGee, 1976). Bock and

Kilakowski (1973) provided evidence which supports the notion that spatial ability is influenced by an X-linked genetic factor, determined by a recessive gene on the X- chromosome. McGee (1979) stated that different assessments of spatial abilities may have different genetic structures. Other authors have explored genetic factors as a cause of ability differences and found little or no evidence for an X-chromosome linkage

(Guttman, 1974; Jardine & Martin, 1984; Linn & Petersen, 1985; Vandenberg & Kuse,

1978). Studies related to practice and training in spatial abilities show that both genders can improve their performance significantly after even short periods of training and this casts doubt on the theory that there is a genetic reason behind differences in spatial ability

(Conner, Schackman, & Serbin, 1978; Connor, Serbin, & Schackman, 1977).

Another avenue of study in the biologic causes of individual differences in spatial ability assessed the influence of personality characteristics. Smith (1964) concluded that those with higher levels of spatial ability tended to be more emotionally stable, possess more self-confidence, have more initiative, and were less neurotic. He also compiled literature that showed that high spatial ability on some types of tests tended to be associated with introversion, aggressiveness, and schizothymic, desurgent, delinquent or asocial traits. Dunn and Eliot (1993) attempted to replicate Smith’s conclusions but found no significant relationship between introversion and results from their battery of spatial tests.

Environmental Factors Related to Individual Differences in Spatial Ability

Many studies have been done which allude to the relationship between spatial ability and participation in certain leisure, academic, professional, and cultural endeavors

(Baenninger & Newcombe, 1989; Lunneborg & Lunneborg, 1984; McDaniel, Guay, Ball,

& Kolloff, 1978; Newcombe & Bandura, 1983; Signorella, Krupa, & Jamison, 1986;

Zimowski & Wothke, 1988). Environmental factors which might influence spatial abilities have been widely studied. In their investigation with infants, Moore and

Johnson (2008) suggested that the factors which influence mental rotation abilities in infants are unknown, but that “by 3 months after birth…male and female infants have already experienced a social world that treats them differently” (p. 1065). Children typically play with toys and engage in activities that are somewhat gender-specific.

Many of the toys and activities (e.g., construction toys, model building, certain computer games, and some sports), especially those associated with males tend to be more spatial in nature and may be somewhat responsible for individual differences in spatial ability

(Voyer, Nolon, & Voyer, 2000).

Numerous questionnaires have been developed to assess patterns of participation in spatial and nonspatial activities, and how these activities compare to measures of spatial ability (Baenninger & Newcombe, 1989; Eliot & Czarnolewski, 2007; McDaniel,

Guay, Ball, & Kolloff, 1978; Newcombe & Bandura, 1983; Olson, Eliot, & Hardy, 1988;

Quaiser-Pohl & Lehmann, 2002; Signorella, Krupa, & Jamison, 1986). Using spatial

55 activities questionnaires, significant, but not always large, correlations have been found between some activities and composite scores on various spatial tests. Women who engaged in activities such as tackle football, high jump, running hurdles, mechanical drawing, car repair, ice hockey, figure skating, dance, gymnastics, building models, carpentry, photography, using compasses, arranging things, and solving math riddles scored well overall on some spatial tests. Men who engaged in playing horseshoes, using hand tools, using a compass, building models, working on cars, furniture repair, and mechanical drawing did well on the some spatial tests (Baenninger & Newcombe, 1989;

Lunneborg & Lunneborg, 1984; Newcombe, Bandura, & Taylor, 1983; Olson & Eliot,

1986; Olson, Eliot, & Hardy, 1988; Signorella, Krupa, & Jamison, 1986; Vandenberg,

Kuse, & Vogler, 1985; Voyer, Nolon, & Voyer, 2000). In general, preference for masculine activities is associated with better spatial performance in women but not in men (Quaiser-Pohl & Lehmann, 2002; Signorella, Krupa, & Jamison, 1986).

Some authors believe that experience with video games is related positively with spatial ability (De Lisi & Cammarano, 1996; Green & Bavelier, 2006). Playing computer games that require spatial knowledge has been related to better performance on mental rotation and other types of spatial tests, but not always for both genders (Cherney, 2008;

De Lisi & Cammarano, 1996; Lunneborg & Lunneborg, 1984; Quaiser-Pohl & Lehmann,

2002).

Because males tend to do better on spatial tests, and because males and females tend to engage in different activities from a young age, McDaniel et al. (1978) developed the Spatial Experience Questionnaire to obtain data about life experiences and compared

56 results to spatial ability scores. The questionnaire consisted of 25 activities which were classified by a panel of judges as either masculine, feminine, or gender neutral. These included activities such as playing checkers, skiing, sketching clothes or automobile designs, and arranging furniture. Subjects who completed the questionnaire were asked to identify their “Extent of Participation” and their “Extent of Enjoyment” for each of the

25 items. The second part of the questionnaire included four spatial-type questions about constructing mental maps, visualizing directions, picturing mathematical equations, and visualizing the rotation of a cube and asked the subject to estimate the difficulty of each.

The authors determined that the questionnaire was able to significantly differentiate men into high and low spatial ability groups based on the total score and both the participation and the enjoyment scores. For women, the total score and the participation sub-score were both able to differentiate between high and low spatial ability females. There was no significant difference between the high and low spatial women for the enjoyment score. Further analysis of the questionnaire results revealed that for men, participation in four activities had the most influence in discriminating between high and low spatial ability: making or repairing furniture, playing pool, reading a map or using a compass, and using machine tools. For women, participation in the following had the most influence in discriminating between high and low spatial abilities: sketching house plans, using hand tools, skiing, putting together jigsaw puzzles, building models, weaving or macramé, and reading a map or using a compass (McDaniel, Guay, Ball, & Kolloff,

1978). Results of this study also suggested that girls who possess superior spatial skills

57 tend to be involved in activities that are deemed to be more masculine in nature (for example using hand tools or building models).

Tests of Spatial Ability

Some of the earliest tests of spatial ability include the Maze Test by Porteus

(1915), paper form board (1918), and the Spatial Relations and Hands Tests by Thurstone

(1918) (Eliot & Smith, 1983; Smith, 1964). Other commonly cited tests in spatial research include the Progressive Matrices by Raven (Caplan, MacPherson, & Tobin,

1985; Guay, 1980; Guttman, 1974; Hegarty & Kozhevnikov, 1999; Johnson & Bouchard,

2007; Zimowski & Wothke, 1988), the Water Level and Rod and Frame Tests by Witkin

(Allen & Hogeland, 1978; Caplan, MacPherson, & Tobin, 1985; Hyde, Geiringer, & Yen,

1975; Linn & Petersen, 1985; Voyer, Voyer, & Bryden, 1995), and the Spatial Relations subtest of the Differential Aptitude Test (Anastakis, Hamstra, & Matsumoto, 2000;

Barratt, 1953; Cochran & Wheatley, 1989; Fennema & Sherman, 1977; Fennema &

Sherman, 1978; Linn & Petersen, 1985; Voyer, Voyer, & Bryden, 1995; Wang, 1993).

These tests and many others that claim to be spatial measures have been found to load on factors other than spatial ability (Caplan, MacPherson, & Tobin, 1985; Eliot, 1980; Guay,

1980; Hyde, Geiringer, & Yen, 1975).

In their meta-analysis of sex differences in spatial ability, Linn and Petersen

(1985) classified spatial ability into three categories: spatial perception, mental rotation, and spatial visualization. Spatial tests were analyzed as they related to these categories.

Voyer, Voyer, and Bryden (1995) suggested that this classification, although somewhat vague and in need of further refinement, was reasonably successful in categorizing spatial ability. Because this model of spatial ability has been supported in these meta-analytic studies, it will serve as the model for this research.

Spatial perception (also sometimes referred to as spatial orientation) requires determination of relationships with respect to one’s own body (Linn & Petersen, 1985;

Voyer, Voyer, & Bryden, 1995). Tests that were found to load on this category of spatial ability in Linn and Petersen’s study included the Rod and Frame Test, the Water Level

Test, and some tests that focused on disembedding or overcoming distracting cues. Other processes that characterize spatial perception tests include the use of gravitational vertical or kinesthetic cues.

Spatial visualization was found to involve complicated, multistep processes when dealing with spatial information. Tests that were found to measure this ability included paper folding and form board tests, surface development, hidden or embedded figures tests, and the Spatial Relations subtest of the Differential Aptitude Test. Tests found in this category tend to need more analytic-type strategies for solution, or an ability to switch solution strategies as needed (Linn & Petersen, 1985).

The third category of spatial ability in this theoretical model was described as mental rotation. Linn and Petersen (1985) found this to be a dimension of ability separate from spatial visualization. It is generally believed that tasks in this category are solved by Gestalt or holistic processing strategies (Guay, 1980; Lohman, 1996; Shepard &

Metzler, 1971). Mental rotations tests developed by Shepard and Metzler, and

Vandenberg and Kuse, the Primary Mental Abilities Space Rotations Test by Thurstone, and the Flags and Cards Tests by French are commonly used to test this ability. The three categories differentiated by Linn and Petersen will serve as the model for spatial ability in this study. With that in mind, tests that are purported to measure these abilities will be discussed. The following four tests include items meant to measure spatial abilities in each of these categories.

The Purdue Spatial Visualization Test (PSVT)

The Purdue Spatial Visualization Test (PSVT) was developed by Roland Guay and published in 1976. There are two versions of the test: one with 36 total items, and one with 90 total items. Both versions of the test are divided into three sections or subtests: Developments, Rotations, and Views. Depending on the version, each of the sections has either twelve or thirty questions. The three subtests were developed to measure a different aspect of spatial ability according to the author. Guay (1976) states that the test can be administered either individually or in a group setting, and that it is appropriate for ages 13 and older. Reliability and validity information for the composite test and each of the subtests is discussed in Chapter Three of this document.

In a study of 217 college undergraduates, Guay (1978) found that males scored significantly higher than females overall, and on all three sections of the 36-item version of the PSVT. The Rotations and Views subtests were found to correlate significantly with the spatial relations subtest of the Differential Aptitude Test which suggests they

60 measure the same mental ability (Kovac, 1989). However, in Kovac’s study with middle school children, the test was found to be gender neutral which caused him to question if this is truly a spatial test (Kovac, 1989).

The Visualization of Developments subtest is comprised of either twelve or thirty two-dimensional developments (patterns) which can be mentally folded into a three- dimensional figure. Each development represents the inside of a three-dimensional figure with a shaded portion representing the bottom surface of the figure (Guay, 1978). Each question in this section consists of the development and five answer options, with only one correct option per item (Guay, 1976). The test has been reported to demonstrate significant male-favored gender differences in elementary school and college students, and a similar significant gender difference in math achievement in the study of younger children (Guay, 1978; Guay & McDaniel, 1977). Guay (1978) reported that this test relies on analytic processing strategies, which he described as involving “explicit trial- and-error checking of relationships between different parts of a figure” (p. 5).

The Rotations subtests consist of twelve or thirty questions which examine how a subject is able to mentally rotate a three-dimensional object. The test was developed as a research tool to measure spatial visualization (McGee’s definition). It has been reported that this test was developed on the basis of two assumptions: “(1) that all existing spatial ability tests vary in the degree to which they evoke the use of analytic versus gestalt processing, and (2) that tests that maximize gestalt processing while minimizing analytic processing are the best measures of spatial ability” (Bodner & Guay, 1997, p. 1436).

Previous studies with this test by the author are noted as evidence of construct validity

61 based on reported holistic processing strategies used to solve items (Guay, 1980). Each question contains a prompt and five answer options with only one correct choice.

Subjects are shown a three dimensional sample object rotated from one position to a different position. They are then shown the question prompt figure and asked to mentally picture this item when it is rotated the same way as the sample, then choose the option that represents its appearance if rotated in this way (Guay, 1976). The thirty item version of the test is reported appropriate for those aged 13 and older. A time limit of 20 minutes is recommended (Guay, 1980). Guay (1978, 1980) reported that this test was designed to minimize analytic processing, and that it appears to require a gestalt or holistic processing strategy where subjects solve items by mentally rotating figures as wholes rather than as parts. The test is arranged with four levels of difficulty in increasing order: 90 degree rotation on one axis, 180 degrees on one axis, 90 degrees on two axes, and 90 degrees on one axis with 180 degrees on another axis. Questions are scored as either right or wrong with a maximum score of 30 and no correction for guessing (Guay, 1980). Internal consistency reliability based on previous studies by Guay and others was reported to be between .82 and .92 (K-R 20) (Bodner & Guay, 1997; Carter, LaRussa, & Bodner, 1987;

Cochran & Wheatley, 1989; Guay, 1980). This test was found to correlate reasonably well with the Shepard-Metzler mental rotation test (r = .61) and with the DAT-SR (r =

.72) which suggests construct validity (Cochran & Wheatley, 1989; Guay, 1980).

Reported significant male-favored gender differences also add to the construct validity

(Guay, 1980). This test has been found to show a significant relationship with participation in spatial activities (Guay, 1978).

Although this test shares some characteristics with the Vandenberg modifications of the Shepard-Metzler rotations test, Bodner (1997) notes several differences: the

Purdue Rotations test items are rotated around their natural axis rather than a strictly vertical axis, the Purdue test items may have hidden parts, and test items may be rotated around more than one axis.

Kovacs (1989) administered this test along with the Visualization of Views subtest of the PSRT and the Differential Aptitude Test to middle-school aged children to evaluate the validity of spatial ability measurement instruments. Statistical analysis of the scores from the three tests showed significant correlations for all three suggesting convergent validity (all tests measure the same construct). Differences between the tests were found when scores were compared to course grades for the students. The Rotations test was correlated positively with “Practical Arts, Science, Social Studies, and Math” (p.

32), the Views test with Science, Math, and Vocabulary, and the DAT with Math only.

None of the tests showed significant gender differences in scores which is at odds with the literature showing that tests of spatial skills favor males. While a majority of those interviewed reported a more holistic strategy in solving items, others reported distinctly analytical strategies for the Rotations test. Based on these criteria, Kovac questioned the validity of this test and whether it was truly measuring spatial ability. On the other hand, this finding could be seen as support for Linn & Petersen’s (1985) contention that gender differences don’t reliably emerge until around the age of 13.

The third subtest of the PSVT is the Views test. Again, there is a twelve item version and a thirty item version. The test presents the subject with a three-dimensional

63 object, drawn within an imaginary cube. One corner of the cube is designated as the viewpoint and the examinee must imagine how the three-dimensional object will appear from that viewpoint. There are five answer options with one correct choice (Guay,

1976). Males have been found to score significantly higher on this test, although no significant relationship was found between this test and birth order, handedness, or spatial experience (Guay, 1978). Gender differences are not always found on this test, and items may be solved more by analytical processes than by spatial processes (Kovac, 1989).

Hidden Figures Tests

There are multiple variations of this type of test, variously called the Hidden

Figures Test, Hidden Patterns Test, Embedded Figures Test, Embedded Pattern Test, or the Group Embedded Figures Test. There are versions for both adults and children.

While these types of tests are commonly described as measures of field dependence/independence (Anastakis, Hamstra, & Matsumoto, 2000; Linn & Petersen,

1985; Lord, 1990; Witkin, Moore, Goodenough, & Cox, 1977), they have also been used to evaluate spatial ability. Ekstrom, French, and Harman (1976) described this type of test as a measure for Flexibility of Closure. It has also been described as a marker measure of figure-ground perception (Davis & Eliot, 1994, p. 399). Linn and Petersen

(1985) classified these types of tests as measures of spatial visualization.

The ETS Hidden Figures Test (Ekstrom, French, & Harman, 1976) is an adaptation of the Embedded Figures Test described by Witkin (1977). The difficulty

64 level for this test is described as high, and it is described as appropriate for adolescents and adults. For this test, the subject is presented with five geometric figures labeled A through E at the top of the page. Below the figures are eight complex patterns in which one of the simple patterns has been embedded. The subject must determine which of the simple patterns is hidden within the complex pattern. The test is given in two parts.

There are 16 complex patterns in each part of the test and subjects are given 12 minutes to complete these 16 items. Scoring for the test is the number of correct answers “minus the number marked incorrectly” (p. 21) to control for guessing (Ekstrom, French, &

Harman, 1976), and subjects should be cautioned that guessing is not to their advantage.

In a 1995 meta-analysis by Voyer, Voyer, and Bryden, 34 studies were included which either used the Embedded Figures Test (30) or the Hidden Figures Test (2) as a measure of sex differences in Spatial Visualization. Some of the studies were done with groups as young as six years old, and others used ages ranging up to 82 years old, however most of the studies were done with young adults (college undergraduate students). Fourteen of the studies reported significant gender differences favoring males,

19 reported no significant gender differences in scores, and one study reported females scored significantly better. The gender difference effect sizes were larger when these types of tests were administered in individual settings than when given in group settings leading the authors to suggest that there may be differences in the ways that men and women respond to testing situations. These authors (Voyer, Voyer, & Bryden, 1995) reported that gender differences were seen as early as 14 years on these tests, but overall the tests in this group are inconsistent in demonstrating reliable gender differences in

65 spatial ability. If this is true, it reflects the findings of Linn and Petersen (1985) who noted that there was little evidence of gender differences in the category of spatial ability which they labeled as spatial visualization.

Mental Rotations Test (MRT)

In 1971, Shepard and Metzler described a spatial test which required “mental rotation in three-dimensional space” (Shepard & Metzler, 1971, p. 703). Their test stimuli consisted of figures comprised of 10 contiguous blocks pictured in a way so as to appear three dimensionally. Subjects were presented with a pair of these figures, one of which was rotated in respect to the other one. The figures could be the same or could be mirror images of each other. The task was to determine quickly and accurately whether the figures were the same or different (mirror images). In 1978, Vandenberg and Kuse described a paper-and-pencil adaptation of the mental rotation test developed by Shepard and Metzler. The Vandenberg and Kuse test was described as a three-dimensional test of spatial visualization which was suitable for group administration. In their adaptation, the stimulus figure must be compared to four options rather than just one as in the original test. In the original 20-item version (Vandenberg & Kuse, 1978), each item consists of a criterion figure, two correct alternatives, and two incorrect distracters. Correct alternatives are always identical to the criterion in structure but are shown in a rotated position; the two incorrect alternatives cannot be matched to the criterion figure. For half the items in the test, the distracters are rotated mirror-images of the criterion, while

66 distracters in the other 10 items show a segment or two of the criterion figure in a rotated position (Vandenberg & Kuse, 1978, p. 599). Subjects are given 10 minutes to complete the test, and the authors recommended that items are scored as correct only when both correct alternatives are chosen, which they explained eliminated the need to correct for guessing.

It has frequently been reported that spatial tests should correlate well with mathematical and science grades, but not with grades in English and courses in humanities. In a study of college students, those enrolled in science-based programs did significantly better on the Mental Rotations Test than those enrolled in arts and humanities type programs (Peters, et al., 1995). This was found to be true, not just with

American students, but also with German and Japanese high school and college students

(Peters, 2005). The Mental Rotations Test has also been shown to correlate significantly with surgical skills and anatomy knowledge (Cohen & Hegary, 2007; Wantzel, Hamsta,

Anastakis, Matsumoto, & Cusimano, 2002).

In an effort to establish construct validity for this test, it has been compared with other commonly used spatial tests as well as verbal and reasoning tests. The test was found to correlate reasonably well with other tests of spatial ability such as the Spatial

Relations Subtest of the Differential Aptitude Test (DAT), Primary Mental Abilities-

Spatial Relations Test, Card Rotations, hidden patterns, paper form board, and Identical

Blocks; it correlated especially well with tests of spatial visualization (Cherney, 2008;

Guillot, Champely, Batier, Thiriet, & Collet, 2007; Jansen-Osmann & Heil, 2007;

Vandenberg & Kuse, 1978; Voyer, et al., 2006). A significant correlation of .51 was

67 found with the ETS Paper Folding Test (Blajenkova, Kozhevnikov, & Motes, 2006).

Cohen and Hegarty (2007) reported a nonsignificant correlation of .32 between the

Mental Rotations Test and the PSVT Visualization of Views subtest. There was a significant correlation with the DAT-SR of .61. (Kaufman, 2007).

Another common characteristic of spatial tests is a low correlation with verbal reasoning tasks. Vandenberg and Kuse (1978) found very low correlations between the

Mental Rotations Test and tests for vocabulary and verbal reasoning. Hegarty et al.

(2006) found correlations of -.01 to .05 between the MRT and verbal ability tests. These low correlations supply evidence that this test measures a trait that is separate from verbal ability, and that it can be differentiated from measures for spatial visualization (Linn &

Petersen, 1985).

One of the most reliable characteristics of this test is the differences in scores between men and women. This test consistently shows a clear gender difference in spatial ability favoring males. This difference has been seen in a variety of population samples and over a wide range of ages in the general population (De Lisi & Cammarano,

1996; Geiser, Lehmann, & Eid, 2008; Guillot, Champely, Batier, Thiriet, & Collet, 2007;

Kaufman, 2007; Li, Zhu, & Nuttall, 2003; Linn & Petersen, 1985; Peters, Laeng, Latham,

Jackson, Zaiyouna, & Richardson, 1995; Voyer, Rodgers, & McCormick, 2004). Peters et al. (1995) found significant gender differences favoring males, and that the effect of gender accounted for almost 18% of the variance in scores. In fact, in the 1985 meta- analysis by Linn and Petersen, the Mental Rotations Test yielded the largest gender difference effect sizes for all ages. Gender differences have been reported to be from .6

68 to almost an entire standard deviation unit with this and other tests of mental rotation

(Linn & Petersen, 1985; Stumpf, 1993; Voyer, Voyer, & Bryden, 1995). Effect sizes for the gender differences with this test have been reported as high as d = 1.01 (Cherney,

2008; Kaufman, 2007; Voyer, et al., 2006). These gender differences remain, even when scoring method, instructions, or timing differences are introduced into the administration process (Delgado & Prieto, 1996; Massa, Mayer, & Bohon, 2005; Masters, 1998; Moe &

Pazzaglia, 2006; Peters, Laeng, Latham, Jackson, Zaiyouna, & Richardson, 1995;

Stumpf, 1993; Voyer, Rodgers, & McCormick, 2004).

The Cube Comparison Test

The Cube Comparison Test is one of the two tests categorized as a measure of spatial orientation in the Educational Testing Services Kit of Factor Referenced Tests

(Ekstrom, French, & Harman, 1976). This test is composed of representations of six- sided cubes, similar to children’s blocks. Each side is identified by a unique number, letter, or symbol. Subjects are presented with two cubes for each question, and must determine if they are the rotated images of the same cube or if the two images represent different cubes. The test is divided into two parts, each with 21 questions. Three minutes per part is recommended. It is suggested that scores be calculated as the number correct minus the number incorrect to correct for guessing.

This test was used in conjunction with other spatial ability tests to differentiate college students into low and high spatial ability groups in a study on learning in a

69 science course (Lord, 1990). It was found to load on a spatial rotation factor when included in a battery of tests administered to a large sample of adults (Johnson &

Bouchard, 2007). Gender and generational differences have been reported with this test.

In a study of twins and their parents, males performed better than females, and children performed better than their parents (Jardine & Martin, 1984).

Studies of Spatial Ability in Healthcare

Many studies of spatial ability have been done to examine the role this trait plays in fields such as engineering. In recent years, researchers have become interested in examining the nature and role of spatial ability in healthcare fields. The majority of the investigations have related to spatial ability as it relates to the study of anatomy (Dev,

Friedman, Dafoe, & Felciano, 1992; Friedman, Dev, Dafoe, Murphy, & Felciano, 1993;

Garg, 2002; Garg, Norman, & Sperotable, 2001; Guillot, Champely, Batier, Thiriet, &

Collet, 2007; Kesner & Linzey, 2005). The role of spatial ability in radiology and surgery has also been explored (Berbaum, Smoker, & Smith, 1985; Hegarty, Keehner,

Khooshabeh, & Montello, 2009; Keehner, et al., 2004b; Nilsson, Hedman, & Ahlqvist,

2007; Risucci, 2002; Sidhu, et al., 2004; Smoker, Berbaum, Luebke, & Jacoby, 1984;

Wantzel, Hamsta, Anastakis, Matsumoto, & Cusimano, 2002). Another avenue of research in spatial ability in healthcare relates to its uses as an admissions gate-keeping tool (Hegarty, Keehner, Khooshabeh, & Montello, 2009; Keehner, et al., 2004b). Despite the wealth of research, there are still many questions about spatial learning and spatial

70 ability as it relates to the medical field. Understanding how spatial ability relates to learning, skill acquisition, and job performance are still areas in need of further research

(Anastakis, Hamstra, & Matsumoto, 2000; Garg, Norman, & Sperotable, 2001; Levinson,

Weaver, Garside, McGinn, & Norman, 2007; Rochford, 1985).

In healthcare, many of the clinical tasks performed by practitioners require a spatial understanding of anatomy. Over the past 25 years, multiple studies have investigated methods and concepts involved in understanding anatomy, both basic and cross-sectional (Garg, Norman, Eva, Spero, & Sharan, 2002; Garg, Norman, &

Sperotable, 2001; Guillot, Champely, Batier, Thiriet, & Collet, 2007; Kesner & Linzey,

2005; Khalil, Payer, & Johnson, 2005; Miller, 2000; Pandey & Zimitat, 2007; Rizzolo &

Stewart, 2006; Rochford, 1985). Rosse (1995) stated “…the ultimate purpose of anatomy education is to assist the student in developing an implicit and fully internalized understanding of the three-dimensional dynamic structure of the living human body so that he or she can apply the appropriate cognitive skills when clinical problems call for anatomical reasoning” (p. 499). Learning anatomy is difficult. It requires memorization of many verbal concepts, but more importantly, it requires that one learn the spatial relationships between the various tissues and organs within the body (Friedman, Dev,

Dafoe, Murphy, & Felciano, 1993; Miller, 2000). Verbal knowledge includes such activities as classification; spatial knowledge would involve location and orientation of three-dimensional objects; the ability to recognize and name a displayed object would exhibit characteristics of both verbal and spatial knowledge (Friedman, Dev, Dafoe,

Murphy, & Felciano, 1993; Rosse, 1995). Proficiency in one area does not necessarily

71 translate into proficiency in another area. A student may be able to discuss information about a structure, but not necessarily be able to recognize or locate the object.

Understanding anatomic relationships becomes even more complex when faced with cross-sectional images. Recognizing an anatomic representation in one plane does not necessarily mean that the student will be able to recognize or locate a particular structure in an alternative visual imaging plane.

Studies on the relationship between spatial skills and anatomy achievement have shown that students with higher level spatial skills tend to do better on both spatially- related test questions and on practical anatomy examinations (Garg, 2002; Garg, Norman,

& Sperotable, 2001; Guillot, Louis, Thiriet, & Collet, 2007; Luursema, Verwey,

Kommers, & Annema, 2008; Rochford, 1985; Smoker, Berbaum, Luebke, & Jacoby,

1984). Spatial ability does not however seem to relate to non-spatial types of anatomy exam questions (Rochford, 1985).

Guillot, Champely, Batier, Thiriet, and Collet (2007) conducted a study to look at various aspects of spatial ability and their relationship with scores on anatomy examinations. They were interested specifically in field dependence/independence, mental imagery, and mental rotation. Based on the literature they reviewed, they expected students who were more field-independent, those who could more easily form mental images, and those with the ability to mentally rotate objects to do better on the examinations given. To test their hypotheses, 184 students (130 men and 54 women) enrolled in an anatomy course completed spatial and visual imagery tests. On the final anatomy examination they found that men scored significantly better than women and

72 that there was a strong relationship between the anatomy examination scores and the spatial test scores, especially the test for mental rotation. They concluded that students with higher spatial abilities, especially those related to mental rotation, would appear to be more successful in learning anatomy. This information could potentially be used to identify students who might need supplemental instruction, or to develop teaching materials to aid those students who lack this ability.

Radiology is a medical specialty that requires a high degree of spatial ability. In the mid 1980s, physicians began to rely heavily on cross-sectional imaging techniques.

This type of imaging was thought by many to require an even higher level of spatial ability since those interpreting the images were required to mentally rotate anatomical information in order to understand what they were seeing (Berbaum, Smoker, & Smith,

1985; Nilsson, Hedman, & Ahlqvist, 2007; Smoker, Berbaum, Luebke, & Jacoby, 1984).

A study undertaken to determine if those training in radiology had an aptitude for perceiving three-dimensional relations was conducted using a surface development spatial test and an author developed Visual Form Reconstruction Test (Smoker, Berbaum,

Luebke, & Jacoby, 1984). Residents’ scores on the two tests were compared with semiannual faculty ratings to determine if the Form Test was predictive of acquisition of radiologic expertise. In this study, the Visual Form Reconstruction test was found to be highly correlated with faculty ratings of resident image interpretation performance. High positive correlations were found with evaluations from neuroradiology and rotations that involved computed tomography (CT) and sonography. This supported the authors’ hypothesis that spatial ability is important in subspecialties involving cross-sectional

73 imaging methods. Although the test was not highly correlated with initial faculty ratings of residents, it was highly correlated with scores for residents in the later periods of training. These rating scores in the later periods of training tend to be more predictive of interpretive ability in radiology (Berbaum, Smoker, & Smith, 1985).

Several authors have proposed a link between spatial ability and surgical skill, but results have been inconclusive. In a short summary article, Anastakis, Hamstra, and

Matsumoto (2000) cited the following reasons for some of the conflict: there has been a lack of theoretical justification for the particular visual-spatial tests used; objective assessments of a specific surgical skill have not been used; and samples have not been homogenous when using general ratings of surgical ability. They suggested that future research should first attempt to determine the nature of individual surgical skills to determine which might require visual-spatial skills and how those skills are involved in these individual processes. They stated “this implies that surgical ability be examined within subspecialties to determine those tasks that involve constructs that lend themselves to psychomotor or visual-spatial abilities assessed” (p. 470). Using subspecialties in surgical skills could also solve an additional problem, by using more homogenous groups to evaluate visual-spatial skills. When these authors consolidated the available research, they were able to establish a hierarchy of visual-spatial skills: perceptual recognition of objects, visual imagery involving 2D representations of the reconstruction of objects from their parts, and visual imagery involving 2D and 3D whole object rotations and translations. They suggested that skills identified through a task inventory of surgical abilities be compared with this hierarchy of visual-spatial skills, and then appropriate

74 spatial tests can be chosen. They also suggested that results of research based on these principles would then have both face validity and construct validity, and ultimately would supply a more theoretical framework on which to build.

In a 2002 study by Wanzel, Hamsta, Anastakis, Matsumoto, and Cusimano surgical residents were given six spatial tests (in order of complexity: snowy-pictures, gestalt completion, shape memory, cube comparison, form board, and mental rotation) and then their ability to learn a spatially complex surgical task was evaluated. This was done to test the authors’ hypothesis that visual-spatial ability is important in development of competency for complex surgical procedures. While there was no relationship between scores on the less complex tests of spatial ability, the authors found a significant relationship between the score on the more complex mental rotation test and ability to successfully complete the complex surgical task. Residents who scored low on the complex spatial tests tended to do poorly on the surgical skill, although their performance improved after a teaching intervention. The authors suggested that this need for supplementary education for students with low scores on mental rotation tests be taken into account by developing additional educational tasks and practice situations.

In a related study, spatial ability was studied as a predictor of surgical skills in more experienced surgeons (Keehner, et al., 2004b). Spatial ability was described here as

“…referring to a set of separable but related cognitive functions concerned with representing and processing spatial information, including visualization, spatial orientation, and speeded mental rotation” (p. 71). Previous studies showed a positive correlation between spatial ability and surgical skills in residents, and the authors were

75 interested in determining if this relationship held with more experienced surgeons. The study sample was composed of 98 physicians who attended one of two videoscopic surgery courses; one group highly experienced in videoscopic surgery, and one group less experienced in this particular skill. A paper folding test to measure spatial ability, a self- completed questionnaire to estimate surgical experience, and instructor evaluations to measure competence were the tools used in the study. The authors found that spatial ability for the entire group was slightly below the published norms for the test (although they noted that the norms were developed with college aged students). While spatial ability did not differ significantly between the two groups, it was a significant predictor of the operative skill in less experienced physicians, but not in the more experienced group. They concluded that spatial ability is less of a factor with skilled surgeons because with experience even complex skills become somewhat proceduralized.

Sidhu et al. (2004) were interested in spatial abilities of endovascular surgeons.

This group of surgeons needs to perform vascular surgery, a three-dimensional task, guided by two-dimensional image displays of the affected anatomy. The authors sought to determine whether innate visuospatial ability could predict novice vascular surgeon performance, whether performance could be improved in novice surgeons after an educational intervention, and whether there was a difference between three-dimensional perception between novice and experienced vascular surgeons. To test their hypotheses a computer-based depth map was developed and tested with both expert and novice vascular surgeons. All novices were given the Surface Development Test and the Mental

Rotations Test to evaluate spatial ability. All completed an exercise using the depth map,

76 and then novices were randomized into a control and a treatment group. The treatment group received an instructional session, and then all (novices and experienced surgeons) completed another exercise with the depth map program. While they found a statistically significant difference between novices and experts prior to the educational intervention, after treatment the educated group performed more similar to the experts. Contrary to other studies, these authors found no statistical relationship between spatial ability and performance on this type of test.

In a study of dental students and dental education, Hegarty, Keehner,

Khooshabeh, and Montello (2009) examined spatial ability and its relationship with anatomy grades and dental laboratory grades. As with other professions in the health care field, dentists must be proficient in anatomy and must be able to interpret cross- sectional images of the head and mouth. As outlined above, many studies have related spatial ability with the mental rotation requirements needed to interpret these cross- sectional types of images. Dental admissions tests currently include a spatial ability component, although there is controversy over whether these types of tests are appropriate to use as part of professional program selection criteria. On one hand, some assume that performance depends on pre-existing abilities. On the other hand, others assume that a particular skill, such as spatial ability, can be acquired.

In the above Hegarty et al. 2009 study, undergraduate psychology students, and dental students in their first and fourth years of training were given multiple spatial ability tests (both available and self-developed). These tests included the Perceptual

Ability Test (PAT) which is part of the Dental Admission Test, and a test of spatial

77 ability developed by these authors (an explanation of this test can be found in Cohen and

Hegarty, 2007). The psychology students were included in the sample to determine if there were differences in spatial abilities between dental students and other groups. The spatial test scores were compared with anatomy and dental restorative laboratory grades for the dental students. Their goals with these comparisons were to determine if spatial ability enhanced success in the dental program and/or if spatial ability improved over the course of the training. Statistical analysis of the results of the tests and comparison with the selected grades revealed no significant relationship between spatial ability and anatomy grades and only a small positive significance between spatial ability and the dental laboratory grades. The PAT was most highly correlated with the dental lab grades.

They found no evidence that dental education enhances spatial ability in general; however, the ability to identify cross-sectional information in teeth was superior in fourth year students compared to first year students.

Interpretation of three-dimensional information from two-dimensional radiographic images is also a critical skill for dental professionals. Nilsson, Hedman, and

Ahlqvist (2007) considered this interpretive ability along with spatial ability in a study of dental students. When interpreting radiographic images, depth can be interpreted using cross-sectional imaging, or by using a method called parallax imaging. Parallax imaging uses an x-ray tube shift between exposures of images to simulate depth. The authors theorized that those with higher spatial ability will be able to more accurately interpret depth-related information using the parallax method than those with less spatial ability.

Spatial ability was assessed using a modified version of the Vandenberg and Kuse (1978)

Mental Rotations Test. The students were assessed in their interpretation skills, given training in depth localization, and then assessed in interpretation again. As expected, men scored significantly better than women on the spatial test. Final radiography test results as well as measures of improvement were both found to have a significant positive correlation with spatial ability scores. Regression models used for the analysis however, explained no more than 28% of the variance which may indicate that there are other factors of importance when dental students are learning this skill.

Summary

Spatial ability has been studied for over 100 years. Many of the tests we use today have evolved from early mechanical and performance tests. These tests were originally developed to evaluate intelligence in those who were illiterate or had difficulty with language skills. Factor analytic studies on large batteries of these tests seemed to indicate that many of these instruments were measuring abilities of a spatial nature.

Various terms have been used for this cognitive skill by researchers over the years. Spatial ability has been seen as a solitary skill by some (Berg, Hertzog, & Hunt,

1982; Zimowski & Wothke, 1988). Factor analytic studies have identified two, (McGee,

1979), three (Barratt, 1953; Guilford, Fruchter, & Zimmerman, 1952), or as many as nine spatial factors (Lohman, 1988). The terms to describe spatial skills are often confusing and sometimes conflicting. For example, spatial visualization has been referred to as S2,

V1, Vz, visualization, general visualization, visuospatial ability, or simply as spatial

79 ability (McGee, 1979). Spatial orientation has variously been referred to as the S factor, spatial relations, spatial perception, and cognition of figural systems (Guilford, Fruchter,

& Zimmerman, 1952; Linn & Petersen, 1985; Lohman, 1988; McGee, 1979).

One of the most reasonable explanations of this ability classifies spatial skills into three categories: spatial perception, spatial visualization, and mental rotation (Linn &

Petersen, 1985; Voyer, Voyer, & Bryden, 1995). Spatial perception and spatial orientation seem to involve tasks that rely on gravitational cues, and subjects solve these tasks by determining relationships with respect to their own body. Spatial visualization involves tasks that require mental manipulation of objects in complicated multistep processes. Mental rotation tasks are those that require rotation, inversion, or other manipulation of two- or three-dimensional figures (Linn & Petersen, 1985; Voyer, Voyer,

& Bryden, 1995).

Studies related to individual differences in spatial ability have followed two main pathways: biologic and environmental. The major question underlying this research is:

Are we born with a certain level of spatial ability or can it be developed and/or improved? Biologic reasons for differences in spatial ability may be related to gender, genetics, brain organization, sex hormone influences, or the functional way that the brain processes visual information. Unfortunately, none of the studies have definitively shown that biologic reasons underlie one’s spatial ability. Individual differences in spatial ability between men and women have received the most attention. Gender differences are generally large for mental rotation tasks, smaller for spatial perception tasks, and inconclusive for spatial visualization tasks.

Environmental causes for differences in spatial ability have also been studied extensively. One of the core beliefs underlying many of these studies in this area is that the activities in which we engage and the environment in which we live strongly influences our level of spatial ability. Many of the toys and activities enjoyed by children are somewhat spatial in nature. Building blocks, model building, certain computer games, and some sports are highly spatial. Males tend to engage in these activities more often than females, and this is hypothesized to underlie the gender differences in spatial ability. Practice effects related to spatial skills have also been seen in several research studies, and this also contributes to beliefs that this skill is not just an inborn ability, but can be enhanced. But again, the evidence is not definitive.

A major problem with much of the spatial research relates to the tests that are used to measure this skill. In spite of years of research, there are no clear guidelines for what many spatial tests actually measure. Many tests claim to be measuring spatial ability, but if spatial ability is a highly complex cognitive skill, no test currently available can legitimately make the assertion that it measures the breadth of this ability.

Spatial ability is commonly believed to be positively correlated with mathematical and science abilities. Studies of engineering students have shown that these students tend to excel in spatial ability tests when compared to other students. Healthcare professionals need a strong background in math and sciences courses, and the skills needed in these professionals are often highly spatial in nature. Research in this area is somewhat limited. Anatomy knowledge and skill has been found to be positively related to spatial ability. Studies of surgeons, radiologists, and dentists have also shown that their

81 professional skills are strongly related to scores on spatial ability tests. Other healthcare professionals, such as occupational therapists, radiographers, and medical laboratory scientists rely on spatial skills to perform their required occupational job tasks. If spatial ability is a critical skill for these professionals, understanding the nature of this cognitive ability could be critical in developing teaching and testing material.

Spatial skills in healthcare professions are critical in estimating lengths and distances, in orienting one’s own body in relation to a patient, in manipulation of equipment, in mentally picturing and rotating representations of anatomy and pathology, and in examining and extracting patterns. In short, spatial skills in healthcare tend to align with the theoretical model of spatial ability proposed by Linn and Petersen (1985) and Voyer, Voyer and Bryden (1995). With that in mind, tests for this study have been chosen to represent the three categories of spatial ability proposed in these meta-analyses.

Their spatial perception term mirrored the definition that others have named spatial orientation. Tests that purport to measure this ability include the ETS Cube Comparison

Test and the Visualization of Views subtest of the Purdue Spatial Visualization Test.

Both of these tests tend to rely on an ability to examine spatial problems with relation to orientation of one’s body. Spatial visualization requires complex, multistep manipulation of spatial information and the ability to disembed spatial patterns. To examine both the complex processes and the disembedding processes, the ETS Hidden Figures Test and the

Visualization of Developments subtest of the Purdue Spatial Visualization Test will be used. The third category of spatial skills involves the mental rotation of two- and three- dimensional figures in the imagination. The best measure of this skill is commonly

82 accepted to be the Mental Rotations Test described by Vandenberg and Kuse (1978).

The Visualization of Rotations subtest of the Purdue Spatial Visualization Test has also been shown to measure mental rotation skills. Because these tests have not been used in this population, examination of the validity and reliability for these measures must be examined before any inferences about their results can be made.

Chapter 3: Design and Methods

This chapter explains the methods, sampling and statistical analysis used in the study. The study is primarily quantitative in nature, supported by qualitative analysis of professional documents and task analyses. This chapter includes a description of the methods employed to investigate three research questions. The population and sample will be described, followed by the instrumentation, data collection, and statistical analysis procedures.

There are many tools available to evaluate spatial abilities. Hundreds of tests have been published in the past 100 years. However, none of these tests have been studied in allied health professional students. Prior to drawing any conclusions about spatial abilities in this population, these tools need to be evaluated for validity.

Therefore, this study has three main purposes: to evaluate the nature of spatial abilities in various healthcare professional students, to evaluate the validity evidence for tests used in measuring spatial ability in this population, and to examine the validity evidence of the

Spatial Experience Questionnaire.

Specifically, the research questions for this study are:

Research Question 1: What spatial skills are used by Allied Medical Professionals in the accomplishment of their occupational duties? Which of these skills are shared across the

84 professions? Do the professions differ in their reliance on spatial perception, spatial visualization, or mental rotation abilities?

Research Question 2: To what extent is validity evidence provided for the use of the

Mental Rotations Test, the Purdue Spatial Visualization Test (PSVT), the Cube

Comparison Test, and The Hidden Figures Test to measure spatial ability in Allied

Medical students?

In order to examine this question, the following assumptions addressing the various aspects of the interpretive argument will be used:

1. Scores on the Cube Comparison, Visualization of Views, Visualization of

Developments, Hidden Figures, Visualization of Rotations, and Mental Rotations

Tests will be able to differentiate level of spatial ability for the Allied Medical

students in this sample.

2. Scores on the Cube Comparison, Visualization of Views, Visualization of

Developments, Hidden Figures, Visualization of Rotations, and Mental Rotations

Tests will demonstrate acceptable reliability.

3. The Cube Comparison, Visualization of Views, Visualization of Developments,

Hidden Figures, and Visualization of Rotations Tests will demonstrate criterion

related validity evidence when compared to the gold standard Mental Rotations

Test.

4. The Cube Comparison Test and the Visualization of Views Test will exhibit

concurrent validity evidence as measures of spatial perception. The Hidden

Figures Test and the Visualization of Developments Test will exhibit concurrent

validity evidence as measures of spatial visualization. The Visualization of

Rotations Test and the Mental Rotations Test will exhibit concurrent validity

evidence as measures of mental rotation.

5. If the Cube Comparison, Visualization of Views, Visualization of Developments,

Hidden Figures, Visualization of Rotations, and Mental Rotations Tests measure

the trait of spatial ability, scores will reflect the male-favored gender differences

commonly found in the literature, and will be positively related to the activities

examined with the Spatial Experience Questionnaire.

Research Question 3: To what extent is validity evidence provided for the use of the

Spatial Experience Questionnaire to measure spatial ability in Allied Medical students?

Population and Sample

Population

This study was designed to evaluate the spatial abilities needed and used in Allied

Medical professions. There are many occupations that can fall under this banner, but not all have the same need of spatial skills. For that reason, the occupations studied include

Athletic Training (AT), Health Information Management and Systems (HIMS), Medical

Dietetics (MD), Occupational Therapy (OT), and Radiologic Sciences (RS). Each of these professions requires a strong background in mathematics and science, especially anatomy, physiology, and pathophysiology. The duties associated with each of these healthcare providers are diverse and extensive (Table 2).

Professions Description of Professional Duties and Job Tasks

Athletic Athletic Trainers (AT) work with physicians, athletic personnel, Training patients and their families, and other medical professionals to provide care in a variety of settings. These professionals are skilled in methods of risk management and injury prevention, and must be able to examine, diagnose, and recommend the appropriate care for an injury (Athletic Training, 2012).

Health Health information management (HIMS) professionals work in a Information variety of settings, and focus on business-related aspects of healthcare. Management Major responsibilities include collection, storage, communication, and and Systems retrieval of healthcare data. They must be knowledgeable about healthcare as well as business and information systems (Health Information Management and Systems, 2012).

Medical Registered Dietitians are food and nutrition experts. They must be Dietetics able to monitor patients, teach and advise, and understand anatomy, pathology, and physiology. They may be involved in activities such as administering nutritional therapy, product development, food and nutrition marketing, or pharmacological research (The Academy of Nutrition and Dietetics, 2012).

Occupational Occupational Therapists (OT) work to enable people to achieve and Therapy maintain the ability to carry out day-to-day activities and live independently. As part of their professional duties, the OT must be able to assess and provide interventions, evaluate the nature and extent of disease and disability, identify environmental barriers to daily activities, and provide and/or develop assistive devices (Description of Occupational Therapy, 2012).

Radiologic Radiologic Science (RS) is the science of using various types of Science radiation (x-ray, magnetism, and ultrasound) to produce images of the tissues, organs, bones, and vessels of the body. Members of this profession implement imaging procedures, manipulate various types of imaging and procedure-related equipment, educate patients and other members of the healthcare team, and provide patient care during diagnostic and therapeutic imaging procedures (Radiologic Sciences and Therapy, 2012).

Table 2. Descriptions of the Allied Medical Professions Included in this Study

Sample

Data were gathered from 128 students in their final academic year in Allied

Medical Professional programs in the School of Health and Rehabilitation Sciences at a large Midwestern university. The sample included students in the following Allied

Medical programs: Athletic Training (AT), Health Information Management and

Systems (HIMS), Medical Dietetics (MD), Occupational Therapy (OT), and Radiologic

Sciences (RS). Faculty members in each of the programs were contacted, and one class period was allocated to administering the test and survey instruments. Students in the sample must have completed at least one year in their respective program to be more representative of professionals in each of these fields. The sample therefore is a convenience sample that is representative of the various spatially oriented health professions. Demographics of the study sample as well as the entire student population in the School of Health and Rehabilitation Sciences (HRS) is found in Table 3.

Ethnicity Total in Sample GPA Gender

M F Asian Black Caucasian Hispanic Other

AT 2 18 3.5 0 0 20 0 0 20

HIMS 13 10 3.45 1 1 20 1 0 23

MD 2 15 3.70 1 0 16 0 0 17

OT 6 33 3.82 1 0 37 0 0 39

RS 10 19 3.63 0 1 26 1 1 29

Sample 33 95 3.64 3 2 119 2 1 128

HRS 308 73 3.28 63 51 886 17 10 1046 Total 8

Table 3. Demographic Information for Sample M = male; F = female

Instrumentation

For this study, four tests have been chosen to correspond to the three categories of spatial ability proposed by Linn and Petersen (1985). This battery of tests includes the following spatial tests: the Mental Rotations Test (Vandenberg & Kuse, 1978), The three- part Purdue Spatial Visualization Test (PSVT; Guay, 1976), The Hidden Figures Test

(Ekstrom, French, & Harman, 1976), and the Cube Comparison Test (Ekstrom, French, &

Harman, 1976). The Mental Rotations Test and the Visualization of Rotations subtest of

89 the PSVT have been used many times to evaluate mental rotation ability. These tests both require that the subject mentally rotate a three dimensional figure. The Hidden

Figures Test and the Visualization of Developments subtest of the PSVT have been used to measure spatial visualization, and the Cube Comparison Test and the Visualization of

Views subtest of the PSVT have been used to evaluate spatial perception ability.

Research has shown that certain types of experiences and activities are related to spatial ability (Baenninger & Newcombe, 1989; Eliot & Czarnolewski, 2007; Lunneborg

& Lunneborg, 1984; McDaniel, Guay, Ball, & Kolloff, 1978; Newcombe, Bandura, &

Taylor, 1983; Newcombe, Dubas, & Baenninger, 1989; Olson & Eliot, 1986). In order to evaluate the relationship between these activities and spatial ability, students will also complete the Spatial Experience Questionnaire (McDaniel, Guay, Ball, & Kolloff, 1978).

Tests to Measure Spatial Perception Ability

Linn and Petersen (1985) describe spatial perception as an ability to orient visual stimuli in relation to oneself or to gravitational fields. Their definition of this term is similar to what other researchers would call spatial orientation (Guilford, 1967; Jardine &

Martin, 1984; Lohman, 1988; Lord, 1990; McGee, 1979). Two of the most commonly used tests to measure this ability are the Water Level Test and the Rod and Frame Test.

Administration and scoring methodology make these tests impractical for large group administration. Other tests that have been used to measure spatial orientation ability include the Spatial Relations subtest of the Primary Mental Abilities Test (Hassler,

Birbaumer, & Feil, 1985), the Cube Comparison Test (Jardine & Martin, 1984; Lord,

1990), Card Rotations (Olson & Eliot, 1986), the Visualization of Views subtest of the

PSVT (Guay, 1980), as well as navigational and landmark tests (Hegarty, Montello,

Richardson, Ishikawa, & Lovelace, 2006). For this study, the tests chosen to measure spatial perception and orientation are the Cube Comparison Test and the Visualization of

Views subtest of the Purdue Spatial Visualization Test. Both of these tests rely strongly on the subject’s ability to orient visual images with respect to gravity, or to imagine a gravitational change in one’s own position.

The Visualization of Views Subtest of the PSVT. The Visualization of Views subtest of the PSVT chosen for this study is a 24 item instrument which is designed to evaluate how subjects can visualize a three-dimensional figure from various perspectives

(Guay, 1976). Guay and McDaniel (1977) describe this test as a measure of high-level spatial ability. They also state that this tool can test “the ability to perceive a three- dimensional object and conceptualize that object sufficiently well to describe portions of it not immediately visible” (McDaniel & Guay, 1976, p. 5). As Figure 1 illustrates, subjects are presented with a drawing of a three-dimensional object enclosed within an imaginary cube which can be thought of as a “glass box”. One corner of the imaginary cube is identified with a black dot. The subject must mentally reorient his or her position so that the black dot lies between them and the central three-dimensional object, and then imagine how it will look from that viewpoint. Each question offers five options from which to choose the correct answer. Students were given 4 minutes to complete the 12 items on the test. The score on the test is simply the number correct.

Figure 1. Example Item from the Visualization of Views Subtest of the Purdue Spatial Visualization Test

Internal consistency reliability estimates for this test or a similar variation have been reported as .56 (K-R 20) in second through seventh grade school children (Guay &

McDaniel, 1977). Guay (1978) reports internal consistency reliability for the composite

PSVT at .92 and for the three subtests as ranging between .65 and .87 (K-R 20) in a group of undergraduate students, although the specific reliability coefficient for this subtest is not specified.

Some evidence of validity includes significant male-favored gender differences which have been reported with the Visualization of Views Test (Guay, 1978; Guay &

McDaniel, 1977). However Kovac (1989) did not find gender differences on this test when examining eighth grade students. The correlation between this test and the Spatial

Relations subtest of the DAT was found to be highly significant at .51 (Kovac, 1989).

Out of the 58 students who took this test, 35 used either object-reorientation or user- reorientation processing strategies (Kovac, 1989). Elementary school children who were high math achievers also scored significantly better than lower achievers on this test

(Guay & McDaniel, 1977). Kovac (1989) found this test to be significantly correlated with grades in science, math, and vocabulary.

The Cube Comparison Test. The Cube Comparison Test is designated as a test of spatial orientation by Ekstrom, French, and Harman in the Kit of Factor Referenced

Cognitive Tests (1976). As illustrated in Figure 2 the examinee is presented with pictures of two three-dimensional cubes. Each of the six sides of the cubes is labeled with a unique letter or symbol. The task is to determine which of the drawings represent drawings of the same cube, and which present drawings that could not be the same cube.

Two example drawings are presented to the examinee and explained; and then three practice problems are presented and explained. The test is composed of two sets of 21 items and three minutes are allowed for each set. The test is scored as the number correct minus the number incorrect to correct for guessing. The authors noted that the test was suitable for grades 8 through 16.

Figure 2. Example Item from the Cube Comparison Test

In a group of 11th and 12th grade students, reliability was reported to be .77 for both males and females, and .84 for college students, although the specific type of reliability was not specified (Ekstrom, French, & Harman, 1976). Correlation between the two parts of the test was reported to be .90 to a group of subjects aged 12 and over

(Smalley, Thompson, Spence, Judd, & Sparkes, 1989). Limited validity data is available 94 for this test. It was used in a battery to determine high and low spatial ability in a group of undergraduate students taking a biology course (Lord, 1990). The test was used as a measure of spatial orientation in a study of 83 adolescent pairs of twins to evaluate sex- linked gender differences in spatial orientation (Jardine & Martin, 1984).

Tests to Measure Spatial Visualization Ability

Spatial visualization tasks generally are more complex than those for spatial perception. Linn and Petersen (1985) describe tests that measure this ability as requiring

“complicated, multistep manipulations of spatially presented information” (p. 1484).

These tests may or may not rely on analytic strategies, but do require that the examinee work quickly and draw on a repertoire of cognitive strategies. Gender differences with these types of tests were generally small. Tests that have been found to measure this ability include embedded/hidden figures tests, paper folding tests, surface development tests, paper form board tests, and block design tests (Linn & Petersen, 1985; Voyer,

Voyer, & Bryden, 1995). To measure spatial visualization, this study used the Hidden

Figures Test (Ekstrom, French, & Harman, 1976), and the Visualization of Developments subtest of the PSVT (Guay, 1976).

The Hidden Figures Test. Although this test is sometimes described as a measure for flexibility of closure, and sometimes as a measure for field dependence—field independence, the nature of the items are complex and contain distracting information.

This type of test is frequently used as a test of spatial visualization (Davis & Eliot, 1994;

Hassler, Birbaumer, & Feil, 1985; Linn & Petersen, 1985; Lord, 1990; Voyer, Voyer, &

Bryden, 1995). The test is considered to have a high level of difficulty and is suitable for grades 8 through 16 (Ekstrom, French, & Harman, 1976). This test consists of 32 questions divided into two 16 question halves. Figure 3 shows an example of a problem from this test. Examinees are presented with five geometric figures at the top of each page of the exam booklet. Below that are complex figures in which one of the reference figures is embedded. Letters corresponding to the reference figures are below the test figures, and the examinee must choose the letter corresponding to the embedded figure within the complex test figure. In the test booklet two example items are presented, and then each 16-item section of the test is allotted 12 minutes. Scoring consists of the number correct minus a fraction of the number marked incorrectly to discourage guessing on the test, according to the ETS Manual; but since the fraction was not specified in the manual, for this study, the test was scored as the number correct.

Figure 3. Example Item from the Hidden Figures Test

Reliability for samples of high school males and females are reported to be .82 and .80, and for college males to be .83 (Ekstrom, French, & Harman, 1976). Davis and

Eliot (1994) report reliabilities in the .80-.83 range. Coefficient alpha of .82 in a sample of college students was reported by Eliot (1984). Although little specific reliability data has been reported for this specific test, other hidden or embedded figures tests report

97 reliabilities in the range of .82 to .95 (Hegarty, Montello, Richardson, Ishikawa, &

Lovelace, 2006; Hyde, Geiringer, & Yen, 1975).

Some evidence of construct validity is evidenced by studies on gender differences with this test. While gender differences in favor of males were found by Davis and Eliot

(1994), no gender differences were found by Hassler, Birbaumer, & Feil, (1985). Gender differences were mixed in the Voyer et al. (1995) meta-analysis with about half of the analyzed studies showing male advantage on this test and about half showing no gender difference. This is consistent with Linn and Petersen’s conclusion that gender differences are small and somewhat inconsistent on tests of spatial visualization (Linn & Petersen,

1985).

The Visualization of Developments Subtest of the PSVT. The Visualization of

Developments subtest is a type of surface development test. In this test, subjects are presented with an unfolded two-dimensional representation (development) of the inside of a three-dimensional object as seen in Figure 4. One surface of the development is shaded to represent the bottom surface of the object. Below each development are five three-dimensional objects, one of which represents the development folded into its three- dimensional shape. The examinee chooses the letter corresponding to the object that would be formed by the folded development. The test is divided into two 12-item sections. Four minutes are allowed for each section. The exam is scored as the number of items marked correctly.

Figure 4. Example Item from the Visualization of Developments Subtest of the Purdue Spatial Visualization Test

Internal consistency reliability for this test has been reported to be .66 (K-R 20) in children grades 2-7 (Guay & McDaniel, 1977) and somewhere between .65 and .87 (K-R

20) in a group of undergraduate students, although the specific reliability coefficient for this subtest is not specified (Guay, 1978). Evidence of validity included significant male gender advantage in a study of college students and in elementary students (Guay, 1978;

Guay & McDaniel, 1977), and significant correlations between this test and math achievement (Guay & McDaniel, 1977). This test also tends to rely on more analytic processing strategies which are found more often in spatial visualization tasks (Guay,

1978; Linn & Petersen, 1985; Lohman, 1989; Voyer, Voyer, & Bryden, 1995).

Tests to Measure Mental Rotation Ability

Mental rotation is the third category of spatial ability in Linn and Petersen’s model. This ability requires that a mental picture of an object be held in the mind and rotated in some direction about its axis. Many tests have been developed to measure this ability including the Card Rotations Test, the Spatial Relations subtest of Thurstone’s

Primary Mental Abilities Test, and various adaptations of the Shepard and Metzler test.

The two tests chosen for this study are the Visualization of Rotations subtest of the PSVT and the Mental Rotation Test developed by Vandenberg and Kuse (1978).

The Visualization of Rotations Subtest of the PSVT. It is commonly believed that mental rotation ability relies heavily on Gestalt or holistic mental processing abilities and this test was developed to maximize this type of processing while minimizing analytic processing (Bodner & Guay, 1997). For this test, subjects are presented with a three- dimensional geometric figure and its image as it is rotated into a different position (see

Figure 5). A second geometric figure is presented and the subject must mentally rotate this figure in the same way as the prompt. Five options are offered with one matching the appropriate rotation of the question prompt. This test contains 24 or 30 questions in two

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12 or15 question sections. Each section is arranged in four levels of difficulty in increasing order: 90 degree rotation on one axis, 180 degree rotation on one axis, 90 degree rotation on two axes, 90 degree rotation on one axis and 180 degree rotation on another axis. One 12 question section was used for this study; a time limit of 4 minutes per section is recommended. Questions are scored as either right or wrong with no correction for guessing (Guay, 1978; Guay, 1980). This test differs somewhat from the

Vandenberg and Kuse Mental Rotations Test. In this test items are rotated around their natural axis rather than a strictly vertical axis, parts of the prompt or test items may be hidden from view, and test items may be rotated around more than one plane.

Figure 5. Example Item from the Visualization of Rotations Subtest of the Purdue Spatial Visualization Test

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Reliability information on this test has been reported with high school and college students. Cronbach’s alpha was reported to be .77 for the 20-item version given to a group of high school geometry students (Battista, 1990). In various studies of college students, reliability has been reported between .78 and .92 (Bodner & Guay, 1997; Carter,

LaRussa, & Bodner, 1987; Cochran & Wheatley, 1989; Guay, 1980).

Evidence of construct validity has been found in studies where respondents report the use of holistic processing strategies (Carter, LaRussa, & Bodner, 1987; Guay, 1980;

Kovac, 1989). Construct and convergent validity are also supported by studies (Bodner

& Guay, 1997; Guay, 1980) which demonstrate reasonably strong correlations with the

Shepard and Metzler mental rotation items (r = .61) and with DAT-SR (r = .72), especially with the more difficult items (Cochran & Wheatley, 1989; Kovac, 1989).

Significant male-favored gender differences have been reported (Bodner & Guay,

1997; Cochran & Wheatley, 1989; Guay, 1980). Results from this test have been significantly and positively correlated with spatial activities (Guay, 1978), and with tests of mechanical and quantitative reasoning (Bodner & Guay, 1997; Guay, 1980), spatial problems in college chemistry (Bodner & Guay, 1997; Carter, LaRussa, & Bodner,

1987), and with science, math, geometry, and social studies grades (Battista, 1990;

Kovac, 1989). In addition, this test was found to have a low correlation with the

Minnesota Paper Form Board Test which has been shown to rely heavily on analytic processing (Bodner & Guay, 1997).

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The Mental Rotations Test. In 1978, Vandenberg and Kuse modified a three- dimensional test of mental rotation so as to be more practical for group administration.

This paper-and-pencil version of the Shepard and Metzler test has become the gold standard in testing metal rotation abilities. As seen in Figure 6, each question is composed of a criterion figure, two correct responses, and two distracters. The criterion figure is composed of ten three-dimensional blocks. Correct alternatives are rotated versions of the criterion figure. There are always two correct alternatives. The distracters are either rotated mirror images of the criterion object or rotation of some part of the criterion object. The task is to determine quickly and accurately whether the figures are the same or different. The original test contained 20 items divided into two 10 question sections. Subjects are given 3 minutes for each section of the test. The authors recommend that items are scored correct only if both correct alternatives are chosen, which they explain eliminates the need to correct for guessing (Vandenberg & Kuse,

1978).

Figure 6. Example Item from the Mental Rotations Test

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Reliability for this test is generally high and has been reported for subjects from ages 12through adulthood. With normal timing and scoring procedures, reported reliabilities are generally between .83 and .91 (Hegarty, Montello, Richardson, Ishikawa,

& Lovelace, 2006; Moe, Meneghetti, & Cadinu, 2009; Stumpf, 1993; Vandenberg &

Kuse, 1978; Voyer, et al., 2006).

The Mental Rotations Test has consistently shown significant male-favored gender differences (Geiser, Lehmann, & Eid, 2008; Heil & Jansen-Osmann, 2008;

Kaufman, 2007; Masters, 1998; Moe, Meneghetti, & Cadinu, 2009; Peters, Lehmann,

Takahira, Takeuchi, & Jordan, 2006; Vandenberg & Kuse, 1978). The effect size for this difference has been reported to be as large as .95 to 1.03 (Cherney, 2008; Linn &

Petersen, 1985; Voyer, Voyer, & Bryden, 1995), and has been seen to hold across several cultural groups (Peters, Laeng, Latham, Jackson, Zaiyouna, & Richardson, 1995; Peters,

Lehmann, Takahira, Takeuchi, & Jordan, 2006). Scores on this test correlate highly with other tests of spatial ability such as the PMA-SR (r = .61), the DAT-SR, Card Rotations

Test, and the Identical Blocks Test (Kaufman, 2007; Vandenberg & Kuse, 1978; Voyer, et al., 2006). Low correlations have been found between this test and tests of verbal reasoning (Vandenberg & Kuse, 1978). Reports of processing strategies place this test toward the holistic end of the continuum (Li, Zhu, & Nuttall, 2003; Moe, Meneghetti, &

Cadinu, 2009; Vandenberg & Kuse, 1978).

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The Spatial Experience Questionnaire

The Spatial Experience Questionnaire is comprised of a list of 25 activities and experiences identified by a panel of judges to be important in the development of spatial ability (McDaniel E. , Guay, Ball, & Kolloff, 1978). The activities include games such as checkers and chess, sports such as skiing and golf, and activities such as sculpting and reading a map. The subject is instructed to examine each of the activities and rate his/her level of participation on a four-point scale using: Very often, Often, Occasionally, and

Never. Using the same set of 25 activities, each is then rated on a five-point scale for extent of enjoyment using: Very much, Much, Little, None, and Never Participated in this

Activity. Fifteen minutes is given to complete the survey. The survey has been found to discriminate between high and low spatial ability in a group of college students, and to identify activities which may be associated to these groups (McDaniel, Guay, Ball, &

Kolloff, 1978). The questionnaire has been found to correlate significantly with the

PSVT-Visualization of Rotations subtest (Guay, 1978), however no other test comparisons are reported in the literature.

Data Collection

In order to answer Research Question 1 (What spatial skills are used by Allied

Medical Professionals in the accomplishment of their job duties? Which of these skills are shared across the professions? Do the professions differ in their reliance on spatial

105 perception, spatial visualization, or mental rotation abilities?), documentation regarding significant job tasks, occupational activities, and critical knowledge was obtained. This information was garnered from professional organization websites, professional certification agencies, and a U. S. Department of Labor occupational website.

To address research questions 2 and 3, after obtaining IRB approval, data were collected through the administration of several spatial tests and a spatial experience questionnaire. In addition to data collected on the tests and questionnaire, the following demographic information was collected for each participant: degree program enrolled in, date of birth, dominant hand (for writing), ethnicity, gender, and GPA.

Instructors in each of the Allied Medical professional programs were contacted by phone to obtain permission to administer the instruments. During one regularly scheduled 90 minute class period the nature of the research and testing procedure were explained to the students. Consent was obtained and the four spatial tests were then administered. Students were informed that participation was completely voluntary and that there would be no grade penalty for not participating in the study. The study instruments were administered in the following order for each group: Cube Comparison

Test version A, Visualization of Views, Visualization of Developments version A,

Hidden Figures, Visualization of Rotations, Mental Rotations Test version A, Spatial

Experience Questionnaire, Cube Comparison Test version B, Visualization of

Developments version B, Mental Rotations Test version B. The first and second versions of the Cube Comparison, Visualization of Developments, and Mental Rotations Tests were separated to reduce practice and memory effects. Written instructions were read for

106 each test to ensure consistency, and a one to two-minute rest break was given between each of the tests. Test and questionnaire answers were recorded on a digital scoring sheet and scored by hand. All scores were rechecked to ensure accuracy.

Data Analysis

Prior to statistical analysis, the accuracy of data entry was examined and missing variables were evaluated. Because the tests of spatial ability used in this study were timed, it is expected that some subjects would not be able to complete all questions for some or all of the tests. The score for the Cube Comparison Test was calculated as the number of correct items minus the number of incorrect items out of a possible 42 in compliance with the test directions (Ekstrom, French, & Harman, 1976). The maximum scores for each of the other tests were the total number correct: 12 for the Visualization of

Views, 16 for the Hidden Figures Test, 24 for the Visualization of Developments Test, 12 for the Visualization of Rotations Test, and 20 for the Mental Rotations Test (Ekstrom,

French, & Harman, 1976; Guay, 1976; Vandenberg & Kuse, 1978).

Prior to the analyses for the specific research questions, descriptive statistics were analyzed for the sample. Frequencies, means, standard deviations, and ranges were calculated from the demographic data. Student counts, means, and standard deviations for each of the spatial abilities tests were calculated for each program as well as for the entire sample. Means and standard deviations for test scores were also calculated by gender. Significance levels for all statistical tests were set at an alpha level of .05 unless

107 otherwise noted. Specific statistical analysis procedures used for each of the research questions are explained below.

Research Question 1: What spatial skills are used by Allied Medical Professionals in the accomplishment of their job duties? Which of these skills are shared across the professions? Do the professions differ in their reliance on spatial perception, spatial visualization, or mental rotation abilities?

It is expected that Allied Medical professionals will share much in the way of spatial ability, but some differences in the specific subcategories of spatial ability will emerge. Examination of task analyses and critical skills will reveal the numerous skills in each profession that have a spatial nature. This analysis may also show clear overlaps or divisions in the nature of spatial abilities needed for each of the various professions.

Investigation of the job analyses, task inventories, certification requirements, and other documents was done using the NVivo® qualitative research tool (QRS

International, 2012). Each item from the above documents was examined by the author for its use of spatial skills. Items were then categorized for each Allied Medical profession into spatial perception tasks, spatial visualization tasks, and/or mental rotation tasks. Job tasks were also examined to determine which were unique to the professions and which were shared by each of the Allied Medical professions studied. These data were used to determine meaningful patterns of spatial ability. Because all of the students in the sample are in medically-related professional programs, it is logical to expect that there will be tasks that are concurrent throughout the professions. On the other hand, the

108 data should also show areas of divergence among the spatial tasks needed for the various professions.

Research Question 2: To what extent is validity evidence provided for the use of the Mental Rotations Test, the Purdue Spatial Visualization Test (PSVT), the Cube

Comparison Test, and The Hidden Figures Test to measure spatial ability in Allied

Medical students?

In order to examine this question, the following assumptions addressing the various aspects of the interpretive argument will be used:

1. Scores on the Cube Comparison, Visualization of Views, Visualization of

Developments, Hidden Figures, Visualization of Rotations, and Mental

Rotations Tests will be able to differentiate level of spatial ability for the

Allied Medical students in this sample.

2. Scores on the Cube Comparison, Visualization of Views, Visualization of

Developments, Hidden Figures, Visualization of Rotations, and Mental

Rotations Tests will demonstrate acceptable reliability.

3. The Cube Comparison, Visualization of Views, Visualization of

Developments, Hidden Figures, and Visualization of Rotations Tests will

demonstrate criterion related validity evidence when compared to the gold

standard Mental Rotations Test.

4. The Cube Comparison Test and the Visualization of Views Test will

exhibit concurrent validity evidence as measures of spatial perception.

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