EXPLORING RESEARCH EIGHTH EDITION Neil J. Salkind University of Kansas Boston Columbus Indianapolis New York San Francisco Upper Saddle River Amsterdam Cape Town Dubai London Madrid Milan Munich Paris Montreal Toronto Delhi Mexico City Sao Paulo Sydney Hong Kong Seoul Singapore Taipei Tokyo Executive Editor: Stephan Frail Editorial Assistant: Madelyn Schricker Marketing Manager: Nicole Kunzmann Marketing Assistant: Jessica Warren Production Assistant: Caitlin Smith Production /Manufacturing Manager: Pat Brown Cover Administrator: Jayne Conte Editorial Production and Composition Service: Hemalatha/ Integra Software Services Pvt. Ltd. Cover Designer: Bruce Kenselaar Printer and Binder: Bind-Rite Graphics Cover Printer: Lehigh-Phoenix Color Cover image: Shotterstock Credits and acknowledgments borrowed from other sources and reproduced, with permission, in this textbook appear on the appropriate page within the text. Appendix A screenshots are all from SPSS, Inc. Copyright © 2012 by Pearson Education, Inc. All rights reserved. Printed in the United States of America. This publication is protected by Copyright and permission should be obtained from the publisher prior to any prohibited reproduction, storage in a retrieval system, or transmission in any form or by any means, electronic, mechanical, photocopying, recording, or likewise. To obtain permission(s) to use material from this work, please submit a written request to Pearson Education, Inc., Permissions Department, One Lake Street, Upper Saddle River, New Jersey 07458 or you may fax your request to 201-236-3290. Many of the designations by manufacturers and seller to distinguish their products are claimed as trademarks. Where those designations appear in this book, and the publisher was aware of a trademark claim, the designations have been printed in initial caps or all caps. Library of Congress Cataloging-in-Publication Data Salkind, Neil J. Exploring research / Neil J. Salkind.—8th ed. p. cm. Includes bibliographical references and index. ISBN-13: 978-0-205-09381-6 (alk. paper) ISBN-10: 0-205-09381-7 (alk. paper) 1. Psychology—Research—Methodology. 2. Education—Research—Methodology. I. Title. BF76.5.S24 2012 150.72—dc22 2011008869 10987654321—14 13 12 11 10 ISBN-10: 0-205-09381-7 ISBN-13: 978-0-205-09381-6 ISBN 10: 0-205-09390-6 ISBN 13: 978-0-205-09390-8 ISBN 10: 0-205-10877-6 ISBN 13: 978-0-205-10877-0 For Sara, Micah and Ted and my fellow Sharks . Happy Laps This page intentionally left blank At a Glance Preface xvii Chapter 1: The Role and Importance of Research 1 Chapter 2: The Research Process: Coming to Terms 21 Chapter 3A: Selecting a Problem and Reviewing the Research 39 Chapter 3B: The Importance of Practicing Ethics in Research 83 Chapter 4: Sampling and Generalizability 95 Chapter 5: Measurement, Reliability, and Validity 109 Chapter 6: Methods of Measuring Behavior 133 Chapter 7: Data Collection and Descriptive Statistics 155 Chapter 8: Introducing Inferential Statistics 177 Chapter 9: Nonexperimental Research: Descriptive and Correlational Methods 197 Chapter 10: Nonexperimental Research: Qualitative Methods 213 Chapter 11: Pre- and True Experimental Research Methods 229 Chapter 12: Quasi-Experimental Research: A Close Cousin to Experimental Research 245 v vi At a Glance Chapter 13: Writing a Research Proposal 259 Chapter 14: Writing A Research Manuscript 273 Appendix A: An Introduction to SPSS 19.x 301 Appendix B: Sample Data Set 363 Appendix C: Answers to End-of-Chapter Exercises 369 Bibliography 387 Glossary 391 Index 401 Contents Preface xvii What’s New in This Edition? xvii How This Book Is Organized xviii What’s Special About This Book? xix A Note to the Instructor xix How to Use This Book xx A Big Thanks xx Chapter 1: The Role and Importance of Research 1 Say Hello to Research! 1 What Research Is and What It Isn’t 2 A Model of Scientific Inquiry 5 Asking the Question 6 Identifying the Important Factors 7 Formulating a Hypothesis 7 Collecting Relevant Information 8 Testing the Hypothesis 8 Working with the Hypothesis 9 Reconsidering the Theory 9 Asking New Questions 9 Different Types of Research 10 Nonexperimental Research 10 Experimental Research 13 True Experimental Research 14 Quasi-Experimental Research 14 What Research Method to Use When? 15 Basic Research Versus Applied Research 15 Summary 17 Exercises 17 Online . 19 Professional Organizations 19 vii viii Contents Chapter 2: The Research Process: Coming to Terms 21 From Problem to Solution 21 The Language of Research 23 All About Variables 23 Dependent Variables 24 Independent Variables 25 The Relationship Between Independent and Dependent Variables 26 Other Important Types of Variables 27 Hypotheses 27 The Null Hypothesis 28 The Research Hypothesis 29 Differences Between the Null Hypothesis and the Research Hypothesis 30 What Makes a “Good” Hypothesis? 31 Samples and Populations 33 The Concept of Significance 33 Summary 34 Exercises 34 Online . 37 Seven Golden Steps 37 The Research Process Helper 37 How to Conduct Research 37 Research 101 37 Chapter 3A: Selecting a Problem and Reviewing the Research 39 Selecting a Problem 40 Defining Your Interests 42 Ideas, Ideas, Ideas (and What to Do with Them) 43 From Idea to Research Question to Hypothesis 44 Reviewing the Literature 46 Using General Sources 48 Using Secondary Sources 50 Using Primary Sources 52 Reading and Evaluating Research 60 What Does a Research Article Look Like? 60 Criteria for Judging a Research Study 61 Using Electronic Tools in Your Research Activities 62 Searching Online 63 Contents ix The Great Search Engines 63 More About Google 65 Using Bibliographic Database Programs 68 Using the Internet: Beyond Searchers 70 Research Activities and the Internet 71 More About E-Mail 71 An Introduction to Usenet (News) Groups 72 Using Mailing Lists or ListServs 76 And, Just a Bit about Web Sites 76 Writing the Literature Review 77 Summary 79 Exercises 79 Online . 81 The Gale Directory of Online, Portable, and Internet Databases 81 The GPO Database List 81 The National Library of Medicine Databases 81 Choosing the Best Search Engine for your Information Need 81 Ready ‘Net Go! 81 Chapter 3B: The Importance of Practicing Ethics in Research 83 A Bit of History 83 Basic Principles of Ethical Research 85 Protection from Harm 85 Maintenance of Privacy 86 Coercion 86 Informed Consent 86 Confidentiality 88 Debriefing 89 Sharing Benefits 89 Ensuring High Ethical Standards 89 The Role of Professional Organizations 90 A Summary of Ethical Guidelines 90 Ethics and Children 91 Ethics Regarding Online Research 92 Summary 93 Exercises 93 Online . 94 Research Methods Knowledge Base 94 Ethics: Why So Important? 94 x Contents Chapter 4: Sampling and Generalizability 95 Populations and Samples 95 Probability Sampling Strategies 96 Simple Random Sampling 96 Systematic Sampling 100 Stratified Sampling 101 Cluster Sampling 102 Nonprobability Sampling Strategies 102 Convenience Sampling 103 Quota Sampling 103 Samples, Sample Size, and Sampling Error 103 How Big Is Big? 105 Estimating Sample Size 105 Summary 106 Exercises 106 Online . 108 The Research Randomizer 108 Doug’s Random Sampling Applet 108 How to Calculate Sample Size 108 Random Number Generator 108 Chapter 5: Measurement, Reliability, and Validity 109 The Measurement Process 109 Levels of Measurement 109 Nominal 111 Ordinal 112 Interval 112 Ratio 113 Continuous Versus Discrete Variables 114 What Is All the Fuss? 114 Reliability and Validity: Why They Are Very, Very Important 115 A Conceptual Definition of Reliability 115 What Makes Up Error Scores? 116 Increasing Reliability 118 How Reliability Is Measured 118 Types of Reliability 119 Establishing Reliability: An Example 122 Validity 123 A Conceptual Definition of Validity 123 Types of Validity 124 Establishing Validity: An Example 126 Contents xi The Relationship Between Reliability and Validity 127 Closing (and Very Important) Thoughts 128 Summary 129 Exercises 129 Online . 131 The Buros Institute 131 The ERIC Test Locator 131 The ETS Test Collection 131 Tests and Test Reviews 131 Screening Tools and Rating Scales 131 Chapter 6: Methods of Measuring Behavior 133 Tests and Their Development 134 Why Use Tests? 134 What Tests Look Like 135 Types of Tests 136 Achievement Tests 136 Multiple-Choice Achievement Items 137 Attitude Tests 142 Personality Tests 145 Observational Techniques 145 Questionnaires 147 Summary 151 Exercises 152 Online . 153 Educational Testing Service 153 FairTest: The National Center for Fair & Open Testing 153 Rethinking Schools 153 Personality Tests 153 Chapter 7: Data Collection and Descriptive Statistics 155 Getting Ready for Data Collection 155 The Data Collection Process 156 Constructing Data Collection Forms 156 Coding Data 159 The Ten Commandments of Data Collection 160 Getting Ready for Data Analysis 161 Descriptive Statistics 162 Distributions of Scores 162 xii Contents Comparing Distributions of Scores 163 Measures of Central Tendency 163 Measures of Variability 165 The Range 166 The Standard Deviation 166 Understanding Distributions 168 The Normal (Bell-Shaped) Curve 168 The Mean and the Standard Deviation 169 Standard Scores: Computing and Using z Scores 170 What z Scores Really, Really Mean 172 Summary 172 Exercises 173 Online . 175 Introduction to Descriptive Statistics 175 Z score Convertor 175 Chapter 8: Introducing Inferential Statistics 177 Say Hello to Inferential Statistics! 177 How Inference Works 177 The Role of Chance 178 The Central Limit Theorem 178 The Idea of Statistical Significance 181 Tests of Significance