Scorekeeping for Conversation-Construction

In this paper, we try to lay the foundation for an informational model of human conversations that formally speci es, for each stage of a conversation, what information is or is not made available to conversants through various forms of \cuings" that occur in the conversation. Squarely facing the fact that multiple lines of cuings often co-occur and interact with each other in the course of an actual conversation, we classify, illustrate, and mathematically characterize their interactions on the basis of Barwise and Seligman's general theory of information ow (1997). A conversation is what conversants construct. Thus, to explain the construction of a conversation is to explain the conversants' behaviors. We may try to do the latter in various ways. With \conversation analysts" (e.g. Sacks et al. 1974), we may appeal to some social conventions that the participants actually attend to and comply with. Or with \discourse analysts" (e.g. Labov and Fanshel 1977), we may appeal to general rules specifying possible sequences of speech acts. Or we might combine two approaches (Traum 1994) or take still another approach. Whatever path we may take, such an endeavor must involve or presuppose some explanation of what information is or is not available to the conversants at a given stage of the conversation. For example, the application of a particular item of the turn-exchange rules would crucially depend on the information available to conversants about the turn-occupancy state at the point; likewise, depending on what information is assumed to be available to a conversant concerning the prior sequence of speech acts, the sequencing rules on speech acts predict di erent behaviors of the participant. In most cases, theorists manage to correctly guess the available information to a participant (by \putting themselves in his or her position") to make speci c predictions about the conversant's behaviors. This practice, however, runs the risk of trivializing whatever theory one may have Also with Nara Advanced Institute of Science and Technology.