Towards a Model for Mixed Initiative in Dialogic Discourse

We are working on representing discourse in a system that we want to support mixed initiative interaction. The basis for this discussion is the authors' work on a system for helping students understand the reasoning behind decision-support systems that use statistical information. The project involves taking an existing system, Banter (Haddawy, Jacobson, & Jr. 1996), in which control of the interaction rests primarily with the system, and redesigning it as a mixed initiative, cooperative agent, a system we call B2. Tutoring systems are a natural testbed for studies of mixed initiative because, at a minimum, the overarching discourse goal is clear: one participant is supposed to come to \know" what the other participant \knows" as a result of the interaction. Both participants are capable of taking control of the interaction to achieve this end.