Conceptual Basis of the Lexicon in Machine Translation

Abstract

This chapter describes the organization and content of lexical information used by unitran, an interlingual machine translation system. Lexical word entries have two levels of description: The first is an underlying form called lexical conceptual structure that is derived from hierarchically organized primitives, and the second is a mapping from this representation to a corresponding syntactic structure. The interaction between these two levels of lexical description is crucial for the fulfillment of two tasks, lexical selection (i.e., word choice) and syntactic realization (i.e., generation of syntactic structure), both of which are necessary for the resolution of a number of different source-language/target-language divergences. The two levels of lexical description and the tasks of lexical selection and syntactic realization are described. In addition, the approach described here is compared to others that have considered the problem of syntactic divergence resolution.