Robust segmentation of Japanese text into a lattice for parsing

要旨

We describe a segmentation component that utilizes minimal syntactic knowledge to produce a lattice of word candidates for a broad coverage Japanese NL parser. The segmenter is a finite state morphological analyzer and text normalizer designed to handle the orthographic variations characteristic of written Japanese, including alternate spellings, script variation, vowel extensions and word-internal parenthetical material. This architecture differs from conventional Japanese wordbreakers in that it does not attempt to simultaneously attack the problems of identifying segmentation candidates and choosing the most probable analysis. To minimize duplication of effort between components and to give the segmenter greater freedom to address orthography issues, the task of choosing the best analysis is handled by the parser, which has access to a much richer set of linguistic information. By maximizing recall in the segmenter and allowing a precision of 34.7%, our parser currently achieves a breaking accuracy of ~97% over a wide variety of corpora.

主題