Transferring Coreference Resolvers with Posterior Regularization

We propose a cross-lingual framework for learning coreference resolvers for resource-poor target languages, given a resolver in a source language. Our method uses word-aligned bitext to project information from the source to the target. To handle task-specific costs, we propose a softmax-margin variant of posterior regularization, and we use it to achieve robustness to projection errors. We show empirically that this strategy outperforms competitive cross-lingual methods, such as delexicalized transfer with bilingual word embeddings, bitext direct projection, and vanilla posterior regularization.