A Grammatical Formalism Based on Patterns of Part-of-Speech Tags

In this paper, we describe a grammatical formalism, called DepPattern, to write dependency grammars using patterns of Part of Speech (PoS) tags augmented with lexical and morphological information. The formalism inherits ideas from Sinclair’s work and Pattern Grammar. To properly analyze semi-fixed idiomatic expressions, DepPattern distinguishes between open-choice and idiomatic rules. A grammar is defined as a set of lexical-syntactic rules at different levels of abstraction. In addition, a compiler was implemented so as to generate deterministic and robust parsers from DepPattern grammars. These parsers identify dependencies which can be used to improve corpus-based applications such as information extraction. At the end of this article, we describe an experiment which evaluates the efficiency of a dependency parser generated from a simple DepPattern grammar. In particular, we evaluated the precision of a semantic extraction method making use of a DepPattern-based parser.

keywords: information extraction, parsing, syntax, pattern grammar, dependency grammar