Japanese Parser on the basis of the Lexical-Functional Grammar Formalism and its Evaluation

We report a Japanese parsing system with a linguistically fine-grained grammar based on the Lexical-Functional Grammar (LFG) formalism. The system is the first Japanese LFG parser with over 97% coverage for real-world text. We evaluated the accuracy of the system comparing it with standard Japanese dependency parsers. The LFG parser shows roughly equivalent performance on the dependency accuracy to the standard parsers. It also provides reasonably accurate results of case detection.