Iowa State University Capstones, Theses and Retrospective Theses and Dissertations Dissertations 1992 A comparison of two navigational aids for hypertext Mark Alan Satterfield Iowa State University Follow this and additional works at: https://lib.dr.iastate.edu/rtd Part of the Business and Corporate Communications Commons, and the English Language and Literature Commons Recommended Citation Satterfield, Mark Alan, "A comparison of two navigational aids for hypertext" (1992). Retrospective Theses and Dissertations. 14376. https://lib.dr.iastate.edu/rtd/14376 This Thesis is brought to you for free and open access by the Iowa State University Capstones, Theses and Dissertations at Iowa State University Digital Repository. It has been accepted for inclusion in Retrospective Theses and Dissertations by an authorized administrator of Iowa State University Digital Repository. For more information, please contact [email protected]. A Comparison of two navigational aids for h3q5ertext by Mark Alan Satterfield A Thesis Submitted to the Gradxiate Facultyin Partial Fulfillment ofthe Requirements for the Degree of MASTER OF ARTS Department: English Major; English (Business and Technical Communication) Signatureshave been redactedforprivacy Iowa State University Ames, Iowa 1992 Copyright © Mark Alan Satterfield, 1992. All rights reserved. u TABLE OF CONTENTS Page ACKNOWLEDGEMENTS AN INTRODUCTION TO USER DISORIENTATION AND NAVIGATION IN HYPERTEXT 1 Navigation Aids 3 Backtrack 3 History 4 Bookmarks 4 Guided tours 5 Indexes 6 Browsers 6 Graphic browsers 7 Table-of-contents browsers 8 Theory of Navigation 8 Schemas ^ 9 Cognitive maps 9 Schemas and maps in text navigation 10 Context 11 Schemas, cognitive maps, and context 12 Metaphors for navigation ' 13 Studies of Navigation Effectiveness 15 Paper vs. hypertext 15 Comparisons between different kinds of aids 17 Implementations of the same aid 18 Comparisons of structure. 19 lU Comparisons of browsers 22 Questions Raised by Previous Work 22 Purpose of the Current Study 23 Variables used in the study 24 . Expected results 26 II. METHOD 28 Subjects 29 Materials 30 The pretest 30 The hypertext documents 31 The task questions 33 The procedural instructions 33 The exit letter 34 Procedure 34 Threats to Internal Validity 36 Data Analysis 37 III. RESULTS 38 Profile Data 38 Directed Task Data 42 IV. DISCUSSION AND CONCLUSIONS 47 Predicted vs. Actual Results 47 Some Factors Affecting the Study 49 Low browser utilization 49 Hypertext size 50 Further study 51 IV Validation studies 51 Presentation strategies 52 Browser tasks 52 V. BIBLIOGRAPHY 54 VI. APPENDIX A: EXAMPLE GRAPHIC BROWSER SCREENS 57 VII. APPENDIX B: EXAMPLE TABLE OF CONTENTS (TOC) BROWSER SCREENS 61 VIII. APPENDIX C: THE PRETEST 65 IX. APPENDIX D: EXAMPLE DATA SCREENS 70 X. APPENDIX E; THE DIRECTED TASK QUESTIONS 73 XI. APPENDIX F: THE PROCEDURAL INSTRUCTIONS 76 XII. APPENDIX G: THE EXIT LETTER 82 V ACKNOWLEDGEMENTS I would like to thank Dr. Patricia Goubil-Gambrell ofIowa State University for allowing me to use her technical writing classes as subjects in this study. I would also like to thank those members ofDr. Goubil-Gambrell's English 314 classes for volunteering to take part in this study. Finally, I would like to thank Anita McVey of Statistical Consulting Services at Iowa State University for her aid in performing the statistical analysis of the data after it was collected. 1 I, AN INTRODUCTION TO USER DISORIENTATION AND NAVIGATION IN HYPERTEXT Hjrpertext is a new form ofcommimication that has been vmder development since the early 1960s (Nielsen, H3rpertext 41). It is commonly defined as a group ofindependent text segments called nodes that are connected ' by links. A link is an associative connection that is maintained by the computer. These links allow the reader to access a node from any other node, which eliminates the single sequential order that is commonly fotmd in most printed texts. Because the reader is given a choice ofpaths through the text, h3rpertext documents are non-sequential in nature (Nielsen, H3TDertext 1). This non sequential reading order is probably one of the most important characteristics of h5rpertext and is simultaneously both an advantage and a disadvantage. A non-sequential reading order is an advantage because it allows technical information to be accessed in a way that meets the needs ofthe audience (Yoimggren 78). Thus, the same document can provide background information to novices in the form of"pop up windows" while giving more advanced users the ability skip the information entirelyifthey so desire (Brown and Russell 163). On the other hand, a non-sequential reading order is a disadvantage because people often become disoriented when they try to find information within the document. This disorientation occurs when they cannot answer three questions: 1. Where should I go next? 2. How can I get back to....? 3. Where am I now? (Wright and Lickorish 97) 2 This problem with user disorientation was noticed early in hypertext research by Van Dam when he was working on the H3^ertext Editing System (889), and he still considered it a serious problem in 1987. His concern about user disorientation was expressed in his ke5mote address at the Association for Computing Machinery's Hypertext '87 conference where he mentioned itas an area that needed further research (894). At the same time in the journal IEEE Computer. Conklin pointed out the "disorientation problem" as one of the two major issues that threaten to limit hypertext's usefulness (38). While the emphasis on the importance of the disorientation problem has not changed much since 1987, some people have not completely supported this view. In 1988, Mark Bernstein asserted that in some situations, such as school assignments, disorientation is not an issue. This assertion was based on his assumption that school assignments are read by instructors who are so familiar with the material that they could not get lost. But Bernstein did acknowledge that user disorientation should be minimized in other situations, such as using technical manuals or other kinds ofscientific or engineering applications of h5^ertext (Bernstein, Compass 35-6). In 1991, he went beyond this stance to call the concern about disorientation "misplaced," and he asserted that user disorientation "is indistinguishable from bad writing" (Bernstein, Deeply 42). While Bernstein made this point in reference to hypertext in general, his argument doesn't completely take into consideration the stringent goals of technical docimientation. These goals include helping the user to find information quickly and with a minimum of effort (Simpson arid Casey 39). Because the purpose of these goals is to help people get their own work done by providing needed information, any problem that disturbs the transfer of knowledge to the 3 reader should not be taken lightly. Therefore, research into the creation ofaids to user navigation and the application of these aids is an important part ofhypertext documentation research. Navigation Aids In the course of conducting research into user disorientation, many different types ofnavigation aids have been invented. The complexity ofthese aids range from a simple backtrack mechanism to a complex integration of artificial intelligence with h3^ertext documents (Carlson 60). The following aids are the ones that are identified most frequently in the literature on hypertext. They are (1) backtrack, (2) history, (3) bookmark, (4) guided tour, (5) indexes, and (6) browsers. The backtrack, history, and bookmark aids are presented first because they are djmaniie. The actual screens that these aids access can change each time the hypertextis used. The last three, on the other hand, are static. They are set up by the author ofthe h5rpertext and they will always provide access to the same screens every time the hypertext is used. Because this study examines browsers, they will be described more completely than the other types of navigational aids. Backtrack The backtrack facility allows the user to jump back to screens that have been previously visited. It greatly reduces any mental stress caused by navigation because users know that they can always invoke the backtrack command to return to an earlier screen. Nielsen considers this to be one ofthe most important of the navigation aids. In order to guarantee its usefiilness, he 4 recommends that the backtrack should be consistently implemented so that it is always invoked in the same manner (Nielsen, Hj^ertext 129), Also, there should not be a limit on the niimber oftimes that a user can backtrack to the next earlier screen from the current screen. The optimimi backtrack implementation would allow the user to retrace his or her path to the starting screen ofthe document. The final point about the backtrack facility is that it should always be available to the user ( Nielsen, Hypertext 129). There should not be any part of the hypertext from which this aid is inaccessible. History A second" way to help the user navigate is the history facility. Like the backtrack facility, it allows the user to return to nodes that have already been visited. But unlike the backtrack facility, which forces the user to retrace his or her path sequentiallyin the data, the history facility allows the user to pick which screen he or she wants to see again. There is no need to travel through other nodes to get to the desired node (Nielsen, Hypertext 129). Bookmarks Because hypertext users may become apprehensive about losing themselves in the doctmient, Mark Bernstein has suggested that a bookmark might help alleviate that fear (Bookmark, 39). The bookmark facility allows the hypertext's readers to save a node to a listifthey think that they will need to return to that node later (Nielsen, Hypertext 130). The resulting list would look much like a history list. The difference is that the contents ofthe bookmark list are totally under the control of the hj^ertext user. This control can be a problem 5 because users may not always immediately realize that the contents ofa node is relevant and therefore fail to put it on the bookmark list.