W. Scott Neal Reilly

Believable Social and Emotional Agents Degree Type: Ph.D. in Computer Science
Advisor(s): Joseph Bates
Graduated: May 1996

Abstract:

One of the key steps in creating quality interactive drama is the ability to create quality interactive characters (or believable agents). Two important aspects of such characters will be that they appear emotional and that they can engage in social interactions. My basic approach to these problems has been to use a broad agent architecture and minimal amounts of modeling of other agent in the environment. This approach is based on an understanding of the artistic nature of the problem.

To enable agent-builders (artists) to create emotional agents, I provide a general framework for building emotional agents, default emotion-processing rules, and discussion about how to create quality, emotional characters. My framework gets a lot of its power from being part of a broad agent architecture. The concept is simple: the agent will be emotionally richer if there are more things to have emotions about and more ways to express them. This reliance on breadth has also meant that I have been able to create simple emotion models that rely on perception and motivation instead of deep modeling of other agents and complex cognitive processing.

To enable agent builders to create social behaviors for believable agents, I have designed a methodology that provides heuristics for incorporating personality into social behaviors and suggests how to model other agents in the environment. I propose an approach to modeling other agents that calls for limiting the amount of modeling of other agents to that which is sufficient to create the desired behavior. Using this technique, I have been able to build robust social behaviors that use surprisingly little representation. I have used this methodology to build a number of social behaviors, like negotiation and making friends.

I have built three simulations containing seven agents to drive and test this work. I have also conducted user studies to demonstrate that these agents appear to be emotional and can engage in non-trivial social interactions while also being good characters with distinct personalities.

Thesis Committee:
Joseph Bates (Chair)
Jaime Carbonell
Reid Simmons
Aaron Sloman (University of Birmingham, England)

James Morris, Head, Computer Science Department
Raj Reddy Dean, School of Computer Science

Keywords:
Artificial Intelligence, Interactive Art, Interactive Drama, Interactive Entertainment, Interactive Fiction, Believable Agents, Emotional Agents, Social Agents, Interactive Characters, Oz, Tok, Em, Agent Architectures, Autonomous Agents, Social Behaviors, Agent Modeling, Personality