Sebastian Padó and Mirella Lapata. 2005. Optimal Constituent Alignment with Edge Covers for Semantic Projection. In Proceedings of the 21st International Conference on Computational Linguistics and 44th Annual Meeting of the Association for Computational Linguistics, 1161-1168. Sydney, Australia.

Given a parallel corpus, semantic projection attempts to transfer semantic role annotations from one language to another, typically by exploiting word alignments. In this paper, we present an improved method for obtaining constituent alignments between parallel sentences to guide the role projection task. Our extensions are twofold: (a) we model constituent alignment as minimum weight edge covers in a bipartite graph, which allows us to find a globally optimal solution efficiently; (b) we propose tree pruning as a promising strategy for reducing alignment noise. Experimental results on an English-German parallel corpus demonstrate improvements over state-of-the-art models.

@InProceedings{Pado:Lapata:05b,
  author =    {Sebastian Pad\'{o} and Mirella Lapata},
  title =     {Optimal Constituent Alignment with Edge Covers for Semantic Projection.},
  crossref =  {ACL:COLING:06},
  pages =     {1161--1168}
}

@Proceedings{ACL:COLING:06,
  title =     {Proceedings of the 21st International Conference on
               Computational Linguistics and 44th Annual Meeting of the Association
               for Computational Linguistics},  
  booktitle = {Proceedings of the 21st International Conference on
               Computational Linguistics and 44th Annual Meeting of the Association
               for Computational Linguistics}, 
  address =    {Sydney, Australia},
  year =       2006
}