Generating Referring Expressions Using Multiple Knowledge Sources

In this paper we present a brief look at some of the knowledge-based processes used in generatii~g referring expressions in the natural language advisory system WlSBER. Although WISBER is fully capable of exploiting syntactic information to generate contextually appropriate references, the work described here concentrates on the use of conceptual and contingent knowledge about objects in the domain of discourse to generate natural-sounding references. A short description of the knowledge sources available is followed by examples of the processes that transform "deep structures" encodimg system intentions into verbalizable form. Finally, we discuss a number of problems of specifier selection and their solution within a knowledge-based framework.