Paper: CoNLL-2011 Shared Task: Modeling Unrestricted Coreference in OntoNotes

ACL ID W11-1901
Title CoNLL-2011 Shared Task: Modeling Unrestricted Coreference in OntoNotes
Venue International Conference on Computational Natural Language Learning
Session shared task
Year 2011
Authors

In this paper, we describe a coreference solver based on the extensive use of lexical fea- tures and features extracted from dependency graphs of the sentences. The solver uses Soon et al. (2001)’s classical resolution algorithm based on a pairwise classification of the men- tions. We applied this solver to the closed track of the CoNLL 2011 shared task (Pradhan et al., 2011). We carried out a systematic optimiza- tion of the feature set using cross-validation that led us to retain 24 features. Using this set, we reached a MUC score of 58.61 on the test set of the shared task. We analyzed the impact of the features on the development set and we show the importance of lexicalization as well as of properties related to dependency links in coreference resolution.