Proceedings of the Annual Meeting of the Cognitive Science Society

This paper offers a mechanism for the generation of expressions that convey a concept to a hearer. These expressions often include rhetorical devices, such as Descriptions and Instantiations. Our mechanism is based on the representation of the preconditions for the understanding of a concept in terms of failures in communication. W e distinguish between two types of communication failures based on their cause: failure due to a hearer's inability to evoke an intended concept, and failure due to the hearer's lack of expertise with respect to the aspects of a concept which are necessary for the comprehension of the discourse. This categorization supports the principled selection of rhetorical devices which are tailored to the prevention of undesirable situations that result in the failure of a communicative goal. These ideas are being implemented in a discourse planner in the domain of high-school algebra.