Conjunction, ellipsis, and other discontinuous constituents in the constituent object parser

Abstract

The Constituent Object Parser (COP) is a domain independent syntactic parser developed for use in information retrieval and similar applications. Its purpose is to extract a simple hierarchical description of a phrase or sentence that can be used in very general pattern matching procedures to determine the structural similarity of sentences or phrases that contain equivalent terms. This paper discusses the mechanisms by which COP handles the problems of conjunction, ellipsis, and discontinuous constituents. These structures are usually particularly difficult to handle in a parser that does not employ domain knowledge or even general semantic knowledge. cop's mechanisms for these structures are directly tailored for, and, in part, even made possible by, the nature of the intended uses of the outputs by the information retrieval matching procedures.