The Impact of a Machine-Readable Lexicon on a Principle Based Parser,

Abstract

The goal of this research was to provide the groundwork for an investigation of an approach to domain independent semantic processing; the combination of a principle based parser (PBP) with a semantically enhanced machine readable dictionary (MRD). The parser is an implementation of Chomsky's Government-Binding theory and therefore provides complete syntactic coverage. The coverage of a parsing system is, however, ultimately a function of the size and richness of its lexicon. To provide both size and richness, the lexicon for the system was extracted from Longman's Dictionary of Contemporary English and semantically enhanced using Roger's International Thesaurus. Increased lexical richness increases system coverage but it may decrease the efficiency of the parser. Therefore, this research investigated the impact of using an MRD as the lexicon for a PBP. The results show that an MRD can indeed be used with a PBP though the larger, more ambiguous lexicon requires controls in the parser to avoid producing a large forest of candidate parse trees. With such controls, the impact of the larger lexicon becomes no greater for a PBP than for a traditional phrase structure grammar (ex., ATN, APSG) dealing with lexical ambiguity.

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Document Details

Document Type
Technical Report
Publication Date
Mar 01, 1996
Accession Number
ADA307955

Entities

People

  • Michael L. Mchale

Organizations

  • Rome Laboratory

Tags

DTIC Thesaurus Topics

  • Ambiguity
  • Dictionaries
  • Efficiency
  • Governments
  • Phrase Structure Grammars

Readers

  • Computational Linguistics
  • Nuclear and Radiation Engineering.
  • Systems Analysis and Design