An agent centered approach to conversational context

Characterizing the context of a conversation is a complex endeavor. In this paper we present some of the key elements that sustain the conversational context. We suggest that a conversation can be viewed as a negotiation game in which participants negotiate on several levels: some of these levels are used to manage the communication (communication channel, information transfer, turn taking) while others (negotiation and environmental sub-contexts) are used to transfer concepts or mental states relative to various spatio-temporal situations between agents. The social and reasoning sub-contexts also play an important role in the characterization of the conversational context. We concentrate on the elements of the negotiation and environmental sub-contexts which make up a core model for the conversational context. We present the key ingredients of those sub-contexts: the agent's perspective that characterizes an agent's temporal position when uttering a sentence; the agent's positioning that specifies the action applied to mental states when an agent plays a move in the negotiation game; mental states and their relations with temporal situations evoked in agents' utterances. We show that all those knowledge structures are temporally situated with respect to a temporal frame of reference whose main reference points are specified relative to agent's perspectives or deictically specified. We emphasize the role of deictic phenomena in the characterization of agents' orientations within the conversational context and thus, the importance of accounting for them in a model of context.