Paper: Coordinate Structure Analysis with Global Structural Constraints and Alignment-Based Local Features

ACL ID P09-1109
Title Coordinate Structure Analysis with Global Structural Constraints and Alignment-Based Local Features
Venue Annual Meeting of the Association of Computational Linguistics
Session Main Conference
Year 2009
Authors

We propose a hybrid approach to coor- dinate structure analysis that combines a simple grammar to ensure consistent global structure of coordinations in a sen- tence, and features based on sequence alignment to capture local symmetry of conjuncts. The weight of the alignment- based features, which in turn determines the score of coordinate structures, is op- timized by perceptron training on a given corpus. A bottom-up chart parsing al- gorithm efficiently finds the best scor- ing structure, taking both nested or non- overlapping flat coordinations into ac- count. We demonstrate that our approach outperforms existing parsers in coordina- tion scope detection on the Genia corpus.