Goal-Based Personalities and Social Behaviors in Believable Agents

Agents are considered ‘‘believable’’ when viewed by an audience as endowed with behaviors, attitudes, and emotions typical of di€ erent personalities. Our work is aimed at realizing believable agents that perform helping behaviors inuenced by their personalities, which we represent as di€ erent clusters of prioritized goals and preferences over plans for achieving goals. The article describes how such a model of personality is implemented in planning with the PRODIGY system and in execution with the RAP system. Both systems are integrated in a plan-based architecture where behaviors characteristic of di€ erent ‘‘helping personality types’’ are automatically designed and executed in a virtual world. The article also shows examples of the kinds of plan produced by PRODIGY for di€ erent personalities and contexts and how such plans are executed by RAP when a helping character interacts with a user in a virtual world.