Conversational Actions and Discourse Situations

We use the idea that actions performed in a conversation become part of the common ground as the basis for a model of context that reconciles in a general and systematic fashion the differences between the theories of discourse context used for reference resolution, intention recognition, and dialogue management. We start from the treatment of anaphoric accessibility developed in DRT, and we show first how to obtain a discourse model that, while preserving DRT’s basic ideas about referential accessibility, includes information about the occurrence of speech acts and their relations. Next, we show how the different kinds of ‘structure’ that play a role in conversation— discourse segmentation, turn-taking, and grounding—can be formulated in terms of information about speech acts, and use this same information as the basis for a model of the interpretation of fragmentary input.