Modeling Side Participants and Bystanders: The Importance of Being a Laugh Track

Research in virtual agents has largely ignored the role and behavior of side participants and especially bystanders. Our view is that the behavior of these other participants is critical in multi-party interactions, especially in interactive drama. In this paper, we provide an analysis of nonverbal behaviors associated with these roles. We first review studies of interpersonal relationships and nonverbal behavior. From this review, we construct an analysis framework based on characters’ interpersonal relationships, conversational roles, and communicative acts. We then assess this framework by analyzing improv sessions of an old west scenario involving 4 characters. Informed by this analysis, we implemented a general model for participant and bystander behavior.