Paper: Trace Prediction And Recovery With Unlexicalized PCFGs And Slash Features

ACL ID P06-1023
Title Trace Prediction And Recovery With Unlexicalized PCFGs And Slash Features
Venue Annual Meeting of the Association of Computational Linguistics
Session Main Conference
Year 2006
Authors

This paper describes a parser which gen- erates parse trees with empty elements in which traces and fillers are co-indexed. The parser is an unlexicalized PCFG parser which is guaranteed to return the most probable parse. The grammar is extracted from a version of the PENN treebank which was automatically anno- tated with features in the style of Klein and Manning (2003). The annotation in- cludes GPSG-style slash features which link traces and fillers, and other features which improve the general parsing accu- racy. In an evaluation on the PENN tree- bank (Marcus et al. , 1993), the parser outperformed other unlexicalized PCFG parsers in terms of labeled bracketing f- score. Its results for the empty cate- gory prediction task and the trace-filler co- indexation task exceed all previously...