Paper: Brutus: A Semantic Role Labeling System Incorporating CCG CFG and Dependency Features

ACL ID P09-1005
Title Brutus: A Semantic Role Labeling System Incorporating CCG CFG and Dependency Features
Venue Annual Meeting of the Association of Computational Linguistics
Session Main Conference
Year 2009
Authors

We describe a semantic role labeling system that makes primary use of CCG-based fea- tures. Most previously developed systems are CFG-based and make extensive use of a treepath feature, which suffers from data spar- sity due to its use of explicit tree configura- tions. CCG affords ways to augment treepath- based features to overcome these data sparsity issues. By adding features over CCG word- word dependencies and lexicalized verbal sub- categorization frames (“supertags”), we can obtain an F-score that is substantially better than a previous CCG-based SRL system and competitive with the current state of the art. A manual error analysis reveals that parser errors account for many of the errors of our system. This analysis also suggests that simultaneous incremental parsing and semant...