Aspectual Properties of Conversational Activities

Segmentation of spoken discourse into distinct conversational activities has been applied to broadcast news, meetings, monologs, and two-party dialogs. This paper considers the aspectual properties of discourse segments, meaning how they transpire in time. Classifiers were con-structed to distinguish between segment boundaries and non-boundaries, where the sizes of utterance spans to represent data instances were varied, and the locations of segment boundaries relative to these in-stances. Classifier performance was better for representations that included the end of one discourse segment combined with the beginning of the next. In addition, classi-fication accuracy was better for segments in which speakers accomplish goals with distinctive start and end points.