Abstract

In this paper, we present a semantic role labeler (or chunker) that groups syntactic chunks (i.e. base phrases) into the arguments of a predicate. This is accomplished by casting the semantic labeling as the classification of syntactic chunks (e.g. NP-chunk, PP-chunk) into one of several classes such as the beginning of an argument (B-ARG), inside an argument (I-ARG) and outside an argument (O). This amounts to tagging syntactic chunks with semantic labels using the IOB representation. The chunker is realized using support vector machines as oneversus-all classifiers. We describe the representation of data and information used to accomplish the task. We participate in the “closed challenge ” of the CoNLL-2004 shared task and report results on both development and test sets. 1

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