CONVERSATIONAL ACTIONS AND DISCOURSE SITUATIONS

We use the idea that actions performed in a conversation become part o f the common ground as the basis for a model of context that reconcile s in a general and systematic fashion the differences between the theo ries of discourse context used for reference resolution, intention rec ognition, and dialogue management. We start from the treatment of anap horic accessibility developed in discourse representation theory (DRT) , and we show first how to obtain a discourse model that, while preser ving DRT's basic ideas about referential accessibility, includes infor mation about the occurrence of speech acts and their relations. Next, we show how the different kinds of 'structure' that play a role in con versation-discourse segmentation, turn-taking, and grounding-can be fo rmulated in terms of information about speech acts, and use this same information as the basis for a model of the interpretation of fragment ary input.