Abstract

The structure of a discourse is reflected in many as- pects of its linguistic realization, including its lexical, prosodic, syntacfic, and semantic nature. Multiparty dialog contains a particular kind of discourse structure, the dialog act (DA). Like other types of structure, the dialog act sequence of a conversation is also reflected in its lexical, prosodic, and syntactic realization. This paper presents a preliminary investigation into the realization of a particular class of dialog acts which play an essential structuring role in dialog, the backchannels or acknowledge- merits tokens. We discuss the lexical, prusodic, and syntactic realization of these and subsumer or re- lated dialog acts like continuers, assessments, yes. answers, agreements, and incipient-speakership. We show that lexical knowledge plays a role in distinguishing these dialog acts, despite the widespread ambiguity of words such as yeah, and that prosodic knowledge plays a role in DA identifica- tion for certain DA types, while lexical cues may be sufficient for the remainder. Finally, our investi- gation of the syntax of assessments suggests that at least some dialog acts have a very constrained syntactic realization, a per-dialog act 'microsyntax'.

Citations