Enhancing Performance of Lexicalised Grammars

Rebecca Dridan, Valia Kordoni

In: ACL-08: HLT. Annual Meeting of the Association for Computational Linguistics: Human Language Technologies (ACL-HLT) 46th June 15-20 Columbus Ohio United States ACL 2008.


This paper describes how external resources can be used to improve parser performance for heavily lexicalised grammars, looking at both robustness and efficiency. In terms of robustness, we try using different types of external data to increase lexical coverage, and find that simple POS tags have the most effect, increasing coverage on unseen data by up to 45\%. We also show that filtering lexical items in a supertagging manner is very effective in increasing efficiency. Even using vanilla POS tags we achieve some efficiency gains, but when using detailed lexical types as supertags we manage to halve parsing time with minimal loss of coverage or precision.


Weitere Links

Deutsches Forschungszentrum für Künstliche Intelligenz
German Research Center for Artificial Intelligence