Building a Lexicon: The Contribution of Computers

This paper presents certain trends in computational analysis of machine-readable dictionaries, from the perspective of using them in the process of (semi-)automatic construction of semantically rich computational lexicons (aka lexical knowledge bases). The concerns of dictionary analysis are related especially to those of lexical semantics, as natural language processing frameworks evolve to seek, and be able to use, richer lexical structures from their lexicons. The paper argues for a particular paradigm of lexicon construction, which relies on having flexible access to fine-grained structural analyses of multiple dictionary sources. To this end, several related issues in computational dictionary analysis are discussed in some detail. In particular, the notion of structured dictionary representation is exemplified by looking at the wide range of functions encoded, both explicitly and implicitly, in the notations for dictionary entries. This allows the formulation of a framework for exploiting the lexical content of dictionary structure, in part encoded configurationaliy, for the purposes of streamlining the process of lexical acquisition. A methodology for instantiating the semantic component of a lexical knowledge base with knowledge derived from existing lexical resources should not be in isolation from a theory of lexical semantics. Rather than promote any particular theory, however, the paper argues that without a theoretical framework the traditional methods of dictionary analysis and data extraction can hardly go further than highlighting the inadequacies of current dictionaries. The paper further argues that by reference to a theory which assumes a formal and rich model of the lexicon, dictionaries can be made to reveal – through guided analysis of highly structured isomorphs - a number of lexical semantic relations of relevance to natural language processing, which are only encoded implicitly and are distributed across the entire source.