THE EFFICACY OF PERSONAL KNOWLEDGE BASES FOR MATERIALIZING MENTAL IMPRESSIONS by STEPHEN C. DAVIES B.S. Rice University, 1992 M.S. University of Colorado, 1996 A thesis submitted to the Faculty of the Graduate School of the University of Colorado in partial fulfillment of the requirement for the degree of Doctor of Philosophy Department of Computer Science 2005 This thesis entitled: The Efficacy of Personal Knowledge Bases for Materializing Mental Impressions written by Stephen C. Davies has been approved for the Department of Computer Science _____________________________________________ Dr. Roger A. King, Committee Chairman _____________________________________________ Dr. Clayton H. Lewis, Committee Member Date _____________ The final copy of this thesis has been examined by the signatories, and we find that both the content and the form meet acceptable presentation standards of scholarly work in the above mentioned discipline. HRC protocol # 0705.13 Davies, Stephen C. (Ph D., Department of Computer Science) The Efficacy of Personal Knowledge Bases for Materializing Mental Impressions Thesis directed by Professor Roger A. King Software tools abound for managing documents and other information sources, but are rarely used to store the mental knowledge readers glean from reading them. Hence our conceptual understanding – perhaps our most precious commodity in the so-called “information age” – is normally left subject to the whims of our erratic memories. This thesis explores the concept of a personal knowledge base: an experimental database and interface designed to store and retrieve a user’s accumulated personal knowledge. It aims to let the user represent information in a way that corresponds more naturally to their mental conceptions than textual notes would. People naturally form mental models of the domains they explore and learn about, and a personal knowledge base allows these to be expressed and archived directly. They need not be converted first to text, a representation which is actually alien to much of the human thought process. A personal knowledge base reflects a user’s own subjective understanding of their world, permitting alternate views of the same objective data. And just as each person has many ideas from different domains tied together through perceived associations, it supports an integrated web of knowledge, potentially mirroring the entire contents of its owner’s mind. After defining the notion of a personal knowledge base precisely, and outlining its role in a user’s life and expected benefits, this thesis provides the design iii rationale for a prototype application. It then presents the results of deploying it to twenty volunteers who used it in real-world settings for extended periods of time. The results suggest that such a tool can be an tremendous asset for a variety of knowledge-related tasks, although commitment, discipline, and a willingness to alter one’s habits are prerequisites for maximum success. It also sheds some light on the ways people typically work with knowledge, and suggests that unless these patterns are changed, they may ultimately form limitations on the effectiveness of such a tool, and indeed on our use of knowledge in general. iv DEDICATION This thesis is dedicated to my Lord and Savior Jesus Christ, Who was its inspiration, power, and hope; and to my devoted wife, Rae, whose patience and encouragement throughout these long, dark years was invaluable. ACKNOWLEDGMENTS I am immeasurably grateful for the contributions of Scotty Allen, Jon Raphaelson, Emil Meng, Jake Engleman, Javier Velez-Morales, Edwin Eng, and Nick Terkay to many aspects of this thesis. Their formative feedback, design insights, and just plain hard work were amazingly beneficial to me. vi CONTENTS Dedication .................................................................................................................... v Acknowledgments ...................................................................................................... vi Contents ..................................................................................................................... vii List of Tables ............................................................................................................... x List of Figures............................................................................................................. xi Chapter 1 Introduction ........................................................................................... 1 Information vs. Knowledge........................................................................................ 2 Attempts to automate the process ............................................................................. 5 An example scenario................................................................................................... 8 Towards a solution.................................................................................................... 18 Chapter 2 Defining the Personal Knowledge Base .............................................. 21 Three essential components of a PKB..................................................................... 24 Benefits of PKBs........................................................................................................ 26 Chapter 3 Literature review .................................................................................. 31 vii Bush’s dream............................................................................................................. 31 Four contributing bodies of research...................................................................... 33 Data models ............................................................................................................... 47 Architecture............................................................................................................... 78 Supplementary features............................................................................................ 85 Summary and critique.............................................................................................. 93 Chapter 4 Popcorn: a prototype personal knowledge base ............................. 99 Design goals ............................................................................................................... 99 The Popcorn data model ........................................................................................ 104 The Popcorn interface ............................................................................................ 109 Architecture and implementation ......................................................................... 121 Evaluation of design goals...................................................................................... 124 Chapter 5 User testing results.............................................................................. 128 Quantitative analysis .............................................................................................. 130 Qualitative impressions .......................................................................................... 144 Summary.................................................................................................................. 168 Chapter 6 Conclusion: knowledge as a commodity........................................... 170 viii Bibliography ............................................................................................................ 175 Appendix A - Database schema for Popcorn prototype...................................... 193 ix LIST OF TABLES Table 1: Terminology employed by a sampling of graph-based knowledge management tools. .......................................................................................................51 Table 2: Summary of knowledge base characteristics across the test group ............131 Table 3: Interview questions to determine why people use Popcorn........................146 Table 4. Interview questions to determine why people don’t use Popcorn. .............148 x LIST OF FIGURES Figure 1. A rendering of a hypothetical “mental impression”.......................................9 Figure 2. The same mental impression after time has passed......................................12 Figure 3. MindManager, a mind map creation tool ...................................................35 Figure 4. CMap, a concept map creation tool..............................................................36 Figure 5. Decision Explorer, a cognitive map creation tool. ......................................38 Figure 6. The NoteCards knowledge management environment.................................40 Figure 7. AquaMinds NoteTaker, a hierarchically-based note-taking application.....42 Figure 8. The TreePad outliner ....................................................................................44 Figure 9. VIKI, one of the first spatial hypertext systems..........................................55 Figure 10. The Presto category-based browser, also known as “Vista” .....................57 Figure 11. Personal Knowbase, a note-taking system based on the category structural framework....................................................................................................................59 Figure 12. Lifestreams, an exclusively chronologically-based information management system.....................................................................................................64 Figure 13. The Aquanet data model............................................................................66