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<Paper uid="W04-2318">
  <Title>Prosodic Cues to Discourse Segment Boundaries in Human-Computer Dialogue</Title>
  <Section position="1" start_page="0" end_page="0" type="abstr">
    <SectionTitle>
Abstract
</SectionTitle>
    <Paragraph position="0"> Theories of discourse structure hypothesize a hierarchical structure of discourse segments, typically tree-structured. While substantial work has been done on identifying and automatically recognizing the textual and prosodic correlates of discourse structure in monologue, comparable cues for dialogue or multi-party conversation, and in particular human-computer dialogue remain relatively less studied. In this paper, we explore prosodic cues to discourse segmentation in human-computer dialogue. Using data drawn from 60 hours of interactions with a voice-only conversational spoken language system, we identify pitch and intensity features that signal segment boundaries. Specifically, based on 473 pairs of segment-final and segment-initiating utterances, we find significant increases for segment-initial utterances in maximum pitch, average pitch, and average intensity, while segment-final utterances show significantly lower minimum pitch. These results suggest that even in the artificial environment of human-computer dialogue, prosodic cues robustly signal discourse segment structure, comparably to the contrastive uses of pitch and amplitude identified in natural monologues.</Paragraph>
  </Section>
class="xml-element"></Paper>