Repairing conversational misunderstandings and non-understandings

Participants in a discourse sometimes fail to understand one another, but, when aware of the problem, collaborate upon or negotiate the meaning of a problematic utterance. To address nonunderstanding, we have developed two plan-based models of collaboration in identifying the correct referent of a description: one covers situations where both conversants know of the referent, and the other covers situations, such as direction-giving, where the recipient does not. In the models, conversants use the mechanisms of refashioning, suggestion, and elaboration, to collaboratively refine a referring expression until it is successful. To address misunderstanding, we have developed a model that combines intentional and social accounts of discourse to support the negotiation of meaning. The approach extends intentional accounts by using expectations deriving from social conventions in order to guide interpretation. Reflecting the inherent symmetry of the negotiation of meaning, all our models can act as both speaker and hearer, and can play both the role of the conversant who is not understood or misunderstood and the role of the conversant who fails to understand.