Improve Parsing Performance by Self-Learning

Yu-Ming Hsieh ； Duen-Chi Yang ； Keh-Jiann Chen

《中文計算語言學期刊》 12卷2期 (2007/06) Pp. 195-216

https://doi.org/10.30019/IJCLCLP.200706.0005

並列摘要

There are many methods to improve performance of statistical parsers. Resolving structural ambiguities is a major task of these methods. In the proposed approach, the parser produces a set of n-best trees based on a feature-extended PCFG grammar and then selects the best tree structure based on association strengths of dependency word-pairs. However, there is no sufficiently large Treebank producing reliable statistical distributions of all word-pairs. This paper aims to provide a self-learning method to resolve the problems. The word association strengths were automatically extracted and learned by parsing a giga-word corpus. Although the automatically learned word associations were not perfect, the constructed structure evaluation model improved the bracketed f-score from 83.09% to 86.59%. We believe that the above iterative learning processes can improve parsing performances automatically by learning word-dependence information continuously from web.

並列關鍵字

Parsing ； Word association ； Knowledge Extraction ； PCFG ； PoS Tagging ； Semantic

參考文獻

Black, E.,S. Abney,D. Flickenger,C. Gdaniec,R. Grishman,P. Harrison,D. Hindle,R. Ingria,F. Jelinek,J. Klavans,M. Liberman,M. Marcus,S. Roukos,B. Santorini,T. Strzalkowski(1991).A Procedure for Quantitatively Comparing the Syntactic Coverage of English Grammars.(Proceedings of the Workshop on Speech and Natural language).

Charniak, E.,M. Johnson(2005).Coarse-to-fine n-best parsing and MaxEnt discriminative reranking.Proceedings of the 43rd Annual Meeting of the Association for Computational Linguistics.(Proceedings of the 43rd Annual Meeting of the Association for Computational Linguistics).:

Chen, K.-J.,C.-R. Huang,F.-Y. Chen,C.-C. Luo,M.-C. Chang,C.-J. Chen,Z.-M. Gao,Anne Abeille, (ed.)(2003).Sinica Treebank: design criteria, representational issues and implementation.Building and Using Parsed Corpora. Text, Speech and Language Technology.20,231-248.

Chen, Y.,M. Asahara,Y. Matsumoto(2004).Deterministic Dependency Structure Analyzer for Chinese.Proceedings of the First International Join Conference on Natural Language Processing.(Proceedings of the First International Join Conference on Natural Language Processing).:

Chiu, C.-M.,J.-Q. Luo,K.-J. Chen(2004).Compositional semantics of mandarin affix verbs.Proceedings of ROCLING XVI: Conference on Computational Linguistics and Speech Processing.(Proceedings of ROCLING XVI: Conference on Computational Linguistics and Speech Processing).: