Paper: Lattice Minimum Bayes-Risk Decoding for Statistical Machine Translation

ACL ID D08-1065
Title Lattice Minimum Bayes-Risk Decoding for Statistical Machine Translation
Venue Conference on Empirical Methods in Natural Language Processing
Session Main Conference
Year 2008
Authors

We present Minimum Bayes-Risk (MBR) de- coding over translation lattices that compactly encode a huge number of translation hypothe- ses. We describe conditions on the loss func- tion that will enable efficient implementation of MBR decoders on lattices. We introduce an approximation to the BLEU score (Pap- ineni et al., 2001) that satisfies these condi- tions. The MBR decoding under this approx- imate BLEU is realized using Weighted Fi- nite State Automata. Our experiments show that the Lattice MBR decoder yields mod- erate, consistent gains in translation perfor- mance over N-best MBR decoding on Arabic- to-English, Chinese-to-English and English- to-Chinese translation tasks. We conduct a range of experiments to understand why Lat- tice MBR improves upon N-best MBR and study the impact ...