Publication
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, USA, ACL, 2008.
Abstract
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.