A model of attention and interest using gaze behavior

One of the major problems of user's interaction with Embodied Conversational Agents (ECAs) is to have the conversation last more than few second: after being amused and intrigued by the ECAs, users may find rapidly the restrictions and limitations of the dialog systems, they may perceive the repetition of the ECAs animation, they may find the behaviors of ECAs to be inconsistent and implausible, etc. We believe that some special links, or bonds, have to be established between users and ECAs during interaction. It is our view that showing and/or perceiving interest is the necessary premise to establish a relationship. In this paper we present a model of an ECA able to establish, maintain and end the conversation based on its perception of the level of interest of its interlocutor.