ABSTRACT CARDONA-RIVERA, ROGELIO ENRIQUE. A Model of Interactive Narrative Affordances. (Under the direction of R. Michael Young and David L. Roberts). Interactive narratives are systems that mediate a player’sinteraction within a virtual environment through a narrative framing. They have become increasingly commonplace in educational, training, and entertainment contexts, but are non-trivial to design and develop. The field of artificial intelli- gence is poised to greatly impact the development of interactive narratives, due to the possibility of algorithmically generating game content. This content creation happens on the basis of a designer’s declarative specification and continues in response to a user’s interaction. Prior work in the area of procedural interactive narrative content generation has focused on algorithmically creating believable interactive narrative environments, without regard to how players will actually act within them. Because a player’sunderstanding of an unfolding story may be partial or incorrect, they may consistently act to advance a story that is incompatible with a designer’sintended narrative experience. Automated content generators therefore face the challenge of generating content that will prompt the player to act in a way intended by an interactive narrative designer, independent of the designer’s intervention. To address this automated design challenge effectively, I argue that content generators must reify the player’s cognition – specifically with regard to their intent – during the process of generation. A player’s intent could fluctuate during gameplay as a function of several factors in two broad categories: (a) structural features of the interactive narrative and (b) the player’s cognitive faculties. This dissertation introduces a model of interactive narrative affordances, which addresses the problem of anticipating the effect on the player’s cognitive faculties on the basis of structural features of the interactive narrative. Interactive narrative affordances are informally defined as opportunities for action that continue a player’s ongoing story experience. They are linked to a player’s anticipatory inferencing, which is a key concern within interactive narrative design practice. In this work, I propose to model the player’s perception of interactive narrative affordances on the basis of their comprehension and inference-making faculties, linked to an automated planning-based representation and automated plan recognition-based reasoning paradigm. The representation is itself useable for procedurally generating an interactive narrative. The model, which I call PERSONA, thus allows us to address the problem of understanding a generated artifact’s effect on the player in a principled manner; on the basis of the same representation used to generate it. In this dissertation I present the model’s theoretical grounding, knowledge representation, reasoning paradigm, and an evaluation in the context of an interactive narrative adventure game procedurally generated from the same inputs to the model. I found partial support for my thesis that an intelligent system can effectively reason about the generation of an interactive narrative and the effect that the generated narrative artifact will have on the cognitive states of human players on the basis of the same knowledge representation and reasoning framework. My analysis contextualizes the partial support in a manner that precludes treating the results as definitive. Instead, this work serves as the groundwork for a number of inter-related inquiries regarding the relationship between procedural content generators, cognition, design, and how those three ultimately can predictably shape gameplay. © Copyright 2019 by Rogelio Enrique Cardona-Rivera All Rights Reserved A Model of Interactive Narrative Affordances by Rogelio Enrique Cardona-Rivera A dissertation submitted to the Graduate Faculty of North Carolina State University in partial fulfillment of the requirements for the Degree of Doctor of Philosophy Computer Science Raleigh, North Carolina 2019 APPROVED BY: R. Michael Young David L. Roberts Co-chair of Advisory Committee Co-chair of Advisory Committee Gabriel Radvansky Robert St. Amant External Member Nicholas T. Taylor DEDICATION To my grandfather, Francisco Rivera Negrón, whom inculcated in me the desire to show up on time, speak honestly, and learn voraciously. Papa, I’m still working on showing up on time. ii BIOGRAPHY The author was born on December 27th, 1987 in San Juan, Puerto Rico, is the brother of Francisco Javier Cardona-Rivera and son of Dr. Rogelio José Cardona Cardona and Wanda Rivera Ortiz. Rogelio completed pre-undergraduate studies at the American Military Academy HS in Guaynabo, Puerto Rico in 2005. He then completed his undergraduate education at the University of Puerto Rico at Mayagüez, earning a Bachelor’s Degree in Computer Engineering with minors in Economics and Mathematics and under the mentorship of Drs. Nayda G. Santiago and J. Fernando Vega- Riveros; prior to graduating, he completed internships at Goldman Sachs in Manhattan, NY, USA in 2008 and the MIT Lincoln Laboratory in Lexington, MA, USA in 2009. Upon graduating in 2010, Rogelio earned the National GEM Consortium’s Ph.D. GEM Fellowship, completing an internship at Apple in Cupertino, CA, USA and subsequently enrolling in North Carolina State University’s Ph.D. Program in Computer Science. During his first year of graduate schooling, Rogelio married his now spouse Allison Grisell Martínez-Arocho, sister of Michael Antonio Martínez-Arocho and Melanie Elizabeth Martínez-Arocho and daughter of Jaime (Jimmy) Antonio Martínez Lozada and Grisell Arocho Arocho. At the end of his first year of graduate schooling, Rogelio earned the Department of Energy’s Computational Science Graduate Fellowship. Rogelio worked as a Visiting Scholar at Sandia National Laboratories in Albuquerque, NM, USA during the summer of 2013 and at the end of that same year earned his en-route Master’s Degree in Computer Science; during that Fall season, Rogelio and Alli adopted their cat, Ash Cardona-Martínez. Rogelio then worked as a Computational Narratologist at Disney Research in Pittsburgh, PA, USA in the first half of 2016. In 2017, prior to finishing his graduate education, Rogelio was recognized as a “New and Future Educator in AI” by the Association for the Advancement of Artificial Intelligence. That same year, Rogelio accepted a position at the University of Utah in Salt Lake City, UT, USA, where he founded his Laboratory for Quantitative Experience Design. In 2019, with the submission of the doc- ument you are currently reading, he completed the requirements of his Ph.D. in Computer Science. Rogelio E. Cardona-Rivera is currently an Assistant Professor within the School of Computing and the Entertainment Arts and Engineering Program at the University of Utah. He researches technologies to improve game design and development through artificial intelligence. Rogelio has published at diverse, high-impact venues in and around intelligent narrative technologies, and his work has been recognized with a Best Paper Award at the International Conference on Interactive Digital Storytelling (ICIDS) in 2012, a Best Student Paper on a Cognitive Science Topic at the Workshop on Computational Models of Narrative in 2012, and an Honorable Mention for Best Paper at the ACM Computer-Human Interaction Conference in 2016. iii ACKNOWLEDGEMENTS I consider myself incredibly fortunate and privileged to have been afforded the opportunity to com- plete a Ph.D. in Computer Science on the topics of computational psychology, artificial intelligence, game design, and interactive narrative. Knowing full well that trying to acknowledge everyone who contributed to my earning this degree is a futile exercise (because any list I create will necessarily be incomplete), in these pages I shall endeavor to complete this task adequately. First and foremost, I simply would not be the human I am today if not for R. Michael Young. I remember visiting NC State during the Graduate Recruiting Weekend and feeling disappointed to know you were going to be out of town at the 2010 Game Developers Conference, only to feel extremely humbled and elated when you offered to chat over the phone. Since that first interaction, every exchange we have ever shared has contributed to the rich tapestry of our relationship. As an adviser, as a mentor, as a colleague, and as a friend: you are of the highest kind, quality, and order. Dave Roberts deserves special recognition as (funnily enough) the first person I met in my newly- formed academic career, during a Graduate Recruiting Weekend at Georgia Tech (the institution he was leaving). Dave, thank you for letting me explore interesting topics, giving me advice on experimental design and statistical measures, offering perspective on “the bigger picture” of the work I was pursuing, listening to incoherent-at-the-time ideas, keeping your door open, and being an incredible mentor. You are a source of inspiration and I count myself fortunate to be a part of your academic lineage. To the rest of my committee, Rob St. Amant, Gabe Radvansky, and Nick Taylor: your thoughtful comments, probing questions, and well-intentioned critiques have unquestionably refined my thinking. I am lucky to have assembled such a constructive dissertation committee. Gabe, meeting you at Notre Dame and interacting with you thereafter catalyzed my thought process in ways I cannot begin to calculate. Nick, it truly is remarkable