A joint model for parsing syntactic and semantic dependencies

This paper describes a system that jointly parses syntactic and semantic dependencies, presented at the CoNLL-2008 shared task (Surdeanu et al., 2008). It combines online Peceptron learning (Collins, 2002) with a parsing model based on the Eisner algorithm (Eisner, 1996), extended so as to jointly assign syntactic and semantic labels. Overall results are 78.11 global F1, 85.84 LAS, 70.35 semantic F1. Official results for the shared task (63.29 global F1; 71.95 LAS; 54.52 semantic F1) were significantly lower due to bugs present at submission time.