Behavior and preference in minimal personality: a study on embodied conversational agents

Endowing embodied conversational agent with personality affords more natural modalities for their interaction with human interlocutors. To bridge the personality gap between users and agents, we designed minimal two personalities for corresponding agents i.e. an introverted and an extroverted agent. Each features a combination of different verbal and non-verbal behaviors. In this paper, we present an examination of the effects of the speaking and behavior styles of the two agents and explore the resulting design factors pertinent for spoken dialogue systems. The results indicate that users prefer the extroverted agent to the introverted one. The personality traits of the agents influence the users' preferences, dialogues, and behavior. Statistically, it is highly significant that users are more talkative with the extroverted agent. We also investigate the spontaneous speech disfluency of the dialogues and demonstrate that the extroverted behavior model reduce the user's speech disfluency. Furthermore, users having different mental models behave differently with the agents. The results and findings show that the minimal personalities of agents maximally influence the interlocutors' behaviors.