User ' s Inferences

In this paper, we describe a content planning mechanism which takes into consideration a user's possible inferences in order to generate the most concise discourse that achieves a given communicative goal. The consideration of a user's inferences results in the addition of information that addresses erroneous inferences , and the omission of easily inferred information. Given a communicative goal, our mechanism applies inference rules in backward reasoning mode to plan rhetorical devices that achieve this goal, and subsequently in forward reasoning mode to conjecture the eeect of these rhetorical devices on the user's beliefs. This process results in one or more sets of rhetorical devices which achieve the intended communicative goal. Each set is then minimized, and the most concise among these sets is selected. These ideas have been implemented in a system called WISHFUL, which generates explanations about concepts.