View article

Work on discourse understanding in artificial intelligence has produced a wide range of seemingly incomparable techniques, each addressing a slightly different problem. A recent paper by Grosz and Sidner (1986) is a first attempt at synthesizing and extending the different approaches into a coherent theory of discourse. Key to their framework is the incorporation of two distinct nonlinguistic componentsthe attentional (related to focus of attention) and the intentional (related to plans and goals) into a theory of discourse structure. However, in task-oriented dialogues' an important distinction must also be made between discourse intentions and another nonlinguistic notion relevant to discourse theory: comrnonsense2 task knowledge. This distinction is needed to account for subdialogues that do not directly correspond to commonsense tasks, for example, clarification and correction subdialogues. In this paper we …