Michael Mateas, of CMU, is working on an intriguing idea wherin avatars are extended to include, somewhat like the Vilhjalmsson and Cassell model, a component that autonomously responds to the virtual world. Here, however, the focus is on creating a window into a character's role in the virtual social fabric. In this way, rather than simply being a static presentation of the user's input, in the virtual world, the avatar becomes a filter of, and window on, that world from a directed cognitive and affective point of view. Motivation for such use of an avatar is that first-person avatar games like Quake, and Doom, do not afford the user any assistance on, or insight into, taking on a given role in the unfolding scenarios -- even though it is often the unique perspective of characters into the dynamically unfolding story-space that is precisely where much of the interest lies.
Mateas gives the example of the the Butler (Anthony Hopkins) in the movie Remains of the Day. To move as only a pure avatar through the external events in this story is to miss everything which drives the telling of these events as literature: it is the perspective of the character -- wherein his highest moral standards dictate that he serve his ``betters'' even when doing this tears assunder the more local fabric of his own life - it is these self-imposed constraints which must be offered to the user if the essence of the work is to be captured. In this way Mateas's work shares with the story-morphing work in the AR [Elliott et al. 1998] the idea that it is the subjective point of view of the characters, not the external plot, that gives depth to the great themes of literature.
Like Doyle's work (below), this is very much a work in progress, but touches on an important, and yet little studied, aspect of avatar-agent representations.