Modifying Beliefs in a Plan-Based Dialogue Model

Researchers [1, 3, 5] have noted that discourse understanding can be enhanced by recognizing a user's goals, and that this recognition process requires reasoning about the agent's beliefs [7]. For example, in order to recognize from utterance IS2 in the following dialogue that the speaker has the communicative goal of expressing surprise at the proposition that Dr. Smith is teaching CIS360 and not just asking if Dr. Smith is teaching CIS420, it is necessary for the system to be able to plausibly ascribe to IS the beliefs that 1) Dr. Smith is teaching CIS420; 2) that this somehow implies that Dr. Smith is not teaching CIS360; and 3) that IP believes that Dr. Smith is teaching CIS360.