Abstract

We consider question-answer dialogues between participants who may disagree with each other. The main problems are: (a) How different speech-acts affect the information in the dialogue; and (b) How to represent what was said in a dialogue, so that we can summarize it even when it involves disagreements (i.e., inconsistencies).We use a fully-typed many-sorted language L with a possible-worlds semantics. L contains nominals representing short answers. The speech-acts are uniformly represented in a dialogue language DL by focus structures, consisting of a mood operator, a topic component and a focus component. Each stage of the dialogue is associated with a set of information functions (g-functions), which are partial functions taking a topic component (representing a question raised) to a set of propositions determined by the corresponding focus component (to the set of answers given to it).