A Computational Approach to Grammatical Coding of English Words

Abstract

As a firs l~ step in many computer language processing systems, each word in a natural language sentence must be coded as to its form-class or part of speech. This paper describes a computational grammar coder which has been completely programmed and is oper~tional on Lhe IBM 7090. It is part of a complete syntactic annlysis system for which it accomplishes word-class coding, using a computational approach rather than the usual method of dictionary lookup. The resulting system is completely contained in less than 1~,000 computer words. It processes running English text on the IBM 7090 at a rate of more than 1250 words per minute. Since the system is not dependent on large dictionaries, it operates on any ordinary English text. In preliminary experiments with scientific text, the system correctly and unambiguously coded over 90 percent of the words in two samples of scientific writing. A fair proportion of the remaining ambiguity can be removed at higher levels of synvactic analysis, but the problem of structural ambiguity in natural languages is seen to be a critical one in the development of practical language processing systems.