BodyChat: autonomous communicative behaviors in avatars

Although avatars may resemble animated communicating interface agents, they have for the most part not profited from recent research into autonomous systems. In particular, even though avatars function within conversational environments (for example, chat or games), and even though they often resemble humans (with a head, hands, and a body) they are incapable of representing the kinds of knowledge that humans have about how to use the body during communication. Their appearance does not translate into increased communicative bandwidth. Face-to-face conversation among humans, however, does make extensive use of the visual channel for interaction management where many subtle and even involuntary cues are read from stance, gaze and gesture. We argue that the modeling and animation of such fundamental behavior is crucial for the credibility and effectiveness of the virtual interaction in chat. By treating the avatar as a communicative agent, we propose a method to automate the animation of important communicative behavior, deriving from work in context analysis and discourse theory. BodyChat is a system that allows users to communicate via text while their avatars automatically animate attention, salutations, turn taking, back-channel feedback and facial expression, as well as simple body functions such as the blinking of the eyes. 1. BEHAVIORS IN AVATARS One type of embodied agent that has received much airplay but little serious research attention in the agent community, is the avatar in a graphical chat. An avatar represents a user in a distributed virtual environment, but has until now not been autonomous. That is, it has not had knowledge to act in the absence of explicit control on the part of the user. In most current graphical chat systems the user is obliged to switch between controlling the avatar behavior and typing messages to other users. While the user is creating the message for her interlocutor, her avatar stands motionless or repeats a selected animation sequence. This fails to reflect the natural relationship between the body and the conversation that is taking place, potentially giving misleading or even conflicting visual