Chapter 6 Discourse and Dialogue 6.1 Overview

The problems addressed in discourse research aim to answer two general kinds of questions: (1) what information is contained in extended sequences of utterances that goes beyond the meaning of the individual utterances themselves? (2) how doesthe context in which an utterance is used a ect the meaning of the individual utterances, or parts of them? Computational work in discourse has focused on two di erent types of discourse: extended texts and dialogues, both spoken and written. Although there are clear overlaps between these|dialogues contain text-like sequences spoken by a single individual and texts may contain dialogues|the current state of the art leads research to focus on di erent questions for each. In addition, application opportunities and needs are di erent. Work on text is of direct relevance to document analysis and retrieval applications whereas work on dialogue is of import for human-computer interfaces regardless of the modality ofinteraction. A good sense of the current state of research in text interpretation can be gained from reading the papers on text interpretation in a recent special issue of Arti cial Intelligence (hereafter, AIJ-SI), (Hobbs, Stickel, et al.