Modalities for building relationships with handheld computer agents.

In this paper we describe the design of a relational agent interface for handheld computers and the results of a study exploring the effectiveness of different user-agent interaction modalities. Four different agent output modalities-text only, static image plus text, animated, and animated plus nonverbal speech-are compared and their impact on the ability of the agent to establish a social bond with the user, the perceived credibility of information delivered, and user acceptance is evaluated. Subjects ranked the two animated versions of the system higher on all measures.