Description Of The LINK System Used For MUC-5


Over the past five years, we have developed a natural language processing (NLP) system called LINK. LINK is a unification-based system, in which all syntactic and semantic analysis is performed in a single step. Syntactic and semantic information are both represented in the grammar in a uniform manner, similar to HPSG ( Pollard and Sag, 1987 ). LINK has been used in several information extraction applications. In a project with General Motors, LINK was used to process terse free-form descriptions of symptoms displayed by malfunctioning automobiles, and the repairs which fixed them. In this very narrow domain, LINK achieved recall and precision rates of 80-85%. Most recently, we used the LINK system to participate in MUC-4. During this competition, we developed initial versions of pre and postprocessing modules which were further developed in MUC-5. In MUC-4, LINK achieved recall and precision rates of about 40%.