tailieunhanh - Báo cáo khoa học: "HPSG Parsing with Shallow Dependency Constraints"

We present a novel framework that combines strengths from surface syntactic parsing and deep syntactic parsing to increase deep parsing accuracy, specifically by combining dependency and HPSG parsing. We show that by using surface dependencies to constrain the application of wide-coverage HPSG rules, we can benefit from a number of parsing techniques designed for highaccuracy dependency parsing, while actually performing deep syntactic analysis. Our framework results in a absolute improvement over a state-of-the-art approach for wide coverage HPSG parsing. . | HPSG Parsing with Shallow Dependency Constraints Kenji Sagae1 and Yusuke Miyao1 and Jun ichi Tsujii1 2 3 department of Computer Science University of Tokyo Hongo 7-3-1 Bunkyo-ku Tokyo Japan 2School of Computer Science University of Manchester 3National Center for Text Mining sagae yusuke tsujii @ Abstract We present a novel framework that combines strengths from surface syntactic parsing and deep syntactic parsing to increase deep parsing accuracy specifically by combining dependency and HPSG parsing. We show that by using surface dependencies to constrain the application of wide-coverage HPSG rules we can benefit from a number of parsing techniques designed for high-accuracy dependency parsing while actually performing deep syntactic analysis. Our framework results in a absolute improvement over a state-of-the-art approach for wide coverage HPSG parsing. 1 Introduction Several efficient accurate and robust approaches to data-driven dependency parsing have been proposed recently Nivre and Scholz 2004 McDonald et al. 2005 Buchholz and Marsi 2006 for syntactic analysis of natural language using bilexical dependency relations Eisner 1996 . Much of the appeal of these approaches is tied to the use of a simple formalism which allows for the use of efficient parsing algorithms as well as straightforward ways to train discriminative models to perform disambiguation. At the same time there is growing interest in parsing with more sophisticated lexicalized grammar formalisms such as Lexical Functional Grammar LFG Bresnan 1982 Lexicalized Tree Adjoining Grammar LTAG Schabes et al. 1988 Head-driven Phrase Structure Grammar HPSG Pollard 624 and Sag 1994 and Combinatory Categorial Grammar CCG Steedman 2000 which represent deep syntactic structures that cannot be expressed in a shallower formalism designed to represent only aspects of surface syntax such as the dependency formalism used in current mainstream dependency parsing. We present a novel framework