Discourse Structure, Grounding, and Prosody in Task-Oriented Dialogue

Abstract

This article explores the relationship between discourse structure, grounding, and prosody in interactive discourse through an empirical analysis of task-oriented dialogue (the Australian Map Task corpus). Our focus is on the role that prosody plays in the process of grounding-the attainment and acknowledgment of mutual knowledge by discourse participants (Clark, 1996). We investigate how patterns of prosodic boundary strengths, pitch contour, pausing, and overlap relate to the structuring of "common ground units" (Nakatani & Traum, 1999), collaborative units that capture the points in the discourse at which common ground is established. We also examine the distribution of dialogue acts (Jurafsky, Shriberg, & Biasca, 1997) within common ground units to add to the emerging model of dialogue structure that takes into account the "joint action" feature of interactive discourse. Our results show that responses belonging to different types of common ground units have different prosodic profiles. These results have implications for computational and psychological modeling of dialogue structure as well as our understanding of the functions of prosody in interaction.