A Scenario-Directed Computational Framework To Aid Decision-Making And Systems Development A Thesis Presented to The Academic Faculty by Reginald L. Hobbs In Partial Fulfillment of the Requirements for the Degree Doctor of Philosophy College of Computing Georgia Institute of Technology August 2005 A Scenario-Directed Computational Framework To Aid Decision-Making And Systems Development Approved by: Dr. Melody M. Moore, Chairman Dr. Spencer Rugaber College of Computing College of Computing Georgia Insitute of Technology Georgia Institute of Technology Dr. Mary Jean Harrold Dr. David Dampier College of Computing Department of Computer Science Georgia Institute of Technology & Engineering Mississippi State University Dr. Leo Mark College of Computing Georgia Institute of Technology Date Approved: August 2005 To Lady MacBeth, thank you for standing by me in this long, but fruitful journey. iii PREFACE Back Off Man, I'm A Scientist! - Dr. Peter Venkman (Bill Murray), Ghost- busters iv ACKNOWLEDGEMENTS No one who achieves success does so without acknowledging the help of others. The wise and confident acknowledge this help with gratitude. – Unknown As I celebrate the silver anniversary of my association with the Georgia Institute of Technology, it is fitting that I reach this milestone by achieving the pinnacle that this fine instititution has to offer. Through 25 years of growth, I have gone from undergraduate stu- dent to airman in the US Air Force to systems administrator to adjunct professor. Through all these varied experiences, I have remained a Tech Man. During my time as both a doctoral student and instructor, I've been approached by my students asking why one seeks a graduate degree. In keeping with my research on the use of narrative, my explanation consisted of a story on the motivation for learning. The story involves three characters, all seekers of truth. The first actor is an undergraduate who approaches the well of knowledge with a large cup, hoping to fill it to the brim with the stuff of learning. The contents enable the bearer to be a useful practitioner in his or her field, capable of dispensing knowledge whenever it is needed. The second actor, the master's graduate, encounters the well using a large bucket that also acts as a filter. This bucket contains not only a much larger amount of information, but concentrated from a specific area of the well. The master's graduate is truly an expert in their chosen discipline. The final protagonist is the doctoral candidate. He is motivated by the desire to create cups, design buckets, and build (and fill) wells. My well building journey has been subsidized by many people who have placed my feet on the path of discovery. First and foremost, I thank God for giving me the opportunity to seek my doctorate and the ability to achieve it. Each challenge has only strengthened my desire to excel and made each surmounted obstacle more satisfying. I am humbled by His grace. I would like to thank Dr. Colin Potts for his advice and for nurturing the spark of a v researcher that existed under a pile of wet kindling. Our many discussions enabled me to think critically, ask the right questions, and seek the right answers. In keeping with the european model for doctoral candidacy, I truly consider myself the world's expert in my particular niche of computer science. To Dr. Jim Gantt, for recognizing my potential and convincing me to become a scientist. Your support, both emotionally and professionally, has been immeasurable. You have been a mentor, in every sense of the word. To my AIRMICS colleagues: Mr. Glenn Racine, Dr. Gerard McCord, Dr. Michael Evans, Mr. Butch Higley, Dr. Mark Kindl, Dr. John (Jay) Gowens, Dr. Adrienne Raglin, Mr. Binh Nguyen, Mr. Son Nguyen, Mr. Brian Rivera and others, thanks for showing what a good and successful research organization feels like and that the phrase "government worker" is not an oxymoron. To my administrative support, Mrs. Patsy Riley, Mrs. Delois Rogers, and Ms. Kim Brinkley, thank you for your ability to cut through the red tape and leap the government beauracracy in a single bound. To Colonel Anthony Love, Colonel Mark Kindl (Ret.), Major Jeffrey (Jay) Reddick, Lieutenant Colonel Rachel Borhaurer, Colonel Ron Byrnes, Major David Dampier (Ret.) and the other military officers that I've had occasion to work with side by side, thanks for showing that the Army can develop critical thinkers and learn how to use them effec- tively. You've shown me that my research can have a positive impact on both the scientific community and my country. To my supervisors at the Army Research Laboratory, particular Mrs. Pat Jones and Dr. Rick Helfman, thanks for your patience in realizing the potential ROI (Return On Investment) that rewards ARL. My carbon-to-diamond transformation into a researcher may well have benefitted from the additional pressure and heat supplied by ARL. To my doctoral committee: Dr. Leo Mark, Dr. Mary Jean Harrold, Dr. Spencer Ru- gaber, and Dr. David Dampier. Thank you for your insight and assistance in manipulating my research ideas into a more palatable form for the larger research community. I'd like to thank Dr. Mark, in his capacity as PhD program coordinator, for helping with what could have been a very awkward transition. vi To my advisor, Dr. Melody Moore, I extend my special gratitude for her advocacy and support. It is a major challenge to establish a mentorship in the later stages of a doctoral program, but you rose to that challenge admirably. Results are the best indicator of your impact; 4 months after you became my advisor, I was doing my defense of research. I was motivated as much by your example and work ethic as by your positive view of my work. I look forward to merging research ideas and having a collaborative impact on the research community. To my mother and father, thanks for your belief in what I could eventually accomplish. Mom, I definitely inherited my fortitude and desire to attempt new things from you. I also inherited a stubbornness that made it impossible for me to quit something I started. Pop, thanks for being a good example of fatherhood and how to keep a family going no matter what happens. To my brother, Rodney, and my sisters, Belinda and Tonja, thanks for being proud of me. It does make a difference to me what you think. To my brother, your accomplishment as a soldier has made me want to have an even greater impact for my country. If my research ends up helping the army, it is because of my desire to have it help you. To my children: Jason, Shikitha, Justin, Jenna, Gino, Jordi, and Jules, thank you for being an even greater accomplishment for me than anything else that I've ever done. I especially want to let Julian, who has never known what it is like for daddy not to be a graduate student, know that I'm now going to be there for you even more. For all my children, thank you for being patient while I sought this doctorate; you've been a large part of my motivation as well. To my loving wife Lisa. It is a bit cliched and not sufficiently strong just to quote that "behind every successful man, there is a strong woman". You've been more than someone behind me pushing; you've been in front of me pulling, beside me nudging, and all around me cheering me on. It is a cosmically huge understatement to say that I couldn't have done this without you. I love you. vii Contents DEDICATION iii PREFACE iv ACKNOWLEDGEMENTS v LIST OF TABLES xii LIST OF FIGURES xiv LIST OF SYMBOLS OR ABBREVIATIONS xvii GLOSSARY xxi SUMMARY xxiv 1 INTRODUCTION 1 1.1 Problem Description . 1 1.2 Motivation . 2 1.3 Research Questions . 4 1.4 Research Contribution . 5 1.5 Thesis Statement . 5 1.6 Overview of Remaining Chapters . 5 2 RELATED WORK 6 2.1 Narrative Applications and Research Efforts . 6 2.1.1 Knowledge Representation for Business Rules . 6 2.1.2 Use Case Scenarios for Business Processes . 8 2.1.3 Case Based Reasoning . 9 2.1.4 StoryML . 11 2.2 Narrative Morphology . 12 2.2.1 Narrative Context . 12 2.2.2 Literary Analysis and Criticism . 15 2.2.3 Film Editing and Screenwriting . 16 2.2.4 Cognitive Mental Models and Thought Experiments . 18 2.2.5 Hypertext . 19 viii 2.2.6 Scenario-Based Design and Requirements Analysis . 19 2.2.7 Use Case Scenarios . 20 2.2.8 Modeling & Simulation Environments . 22 2.2.9 Decision Theory and Decision Analysis . 23 2.2.10 Interactive narrative and role-playing games . 24 2.3 Summary . 25 3 THE HYPERSCENARIO FRAMEWORK 26 3.1 Motivation . 27 3.2 Scenario Concepts, Modeling, and Representation . 31 3.2.1 Scenario Structural Model . 31 3.2.2 Dynamic Model and Scenario Construction . 43 3.2.3 Scenario Querying for Decision-Making . 58 3.3 Scenario Grammar . 61 3.4 Scenario Language Implementation . 65 3.4.1 XML Overview . 67 3.4.2 Scenario Markup Language (SCML) . 69 3.5 Creating Scenarios in SCML . 78 3.5.1 Requirements for using SCML for a Narrative Domain . 78 3.5.2 Limitations of SCML and the hyperscenario framework . 79 3.5.3 Heuristics for finding scenarios for SCML Encoding . 81 3.6 Summary . 83 4 SCENARIO APPLICATIONS 86 4.1 Scenario Generation . 86 4.1.1 Scenario Generator Architecture . 86 4.1.2 Scenario Generator Prototype . 89 4.2 SCML-based Decision Support for Military Planning .