A Collaborative Planning Approach to Discourse Understanding

Approaches to discourse understanding fall roughly into two categories: those that treat mental states as elemental and thus reason directly about them, and those that do not reason about the beliefs and intentions of agents themselves, but about the propositions and actions that might be considered objects of those beliefs and intentions. The rst type of approach is a mental phenomenon approach, the second a data-structure approach (Pollack, 1986b). In this paper, we present a mental phenomenon approach to discourse understanding and demonstrate its advantages over the data-structure approaches used by other researchers. The model we present is based on the SharedPlans are shown to provide a computationally realizable model of the intentional component of Grosz and Sidner's theory of discourse structure (Grosz and Sidner, 1986). Additionally, this model is shown to simplify and extend approaches to discourse understanding that introduce multiple types of plans to model an agent's motivations for for their comments on previous drafts of this paper and on the research presented within it. I especially thank Professors Grosz, Pollack, and Shieber for their invaluable suggestions on strengthening the main points of this paper.