Paper: Exact Decoding for Phrase-Based Statistical Machine Translation

ACL ID D14-1131
Title Exact Decoding for Phrase-Based Statistical Machine Translation
Venue Conference on Empirical Methods in Natural Language Processing
Session Main Conference
Year 2014
Authors

The combinatorial space of translation derivations in phrase-based statistical ma- chine translation is given by the intersec- tion between a translation lattice and a tar- get language model. We replace this in- tractable intersection by a tractable relax- ation which incorporates a low-order up- perbound on the language model. Exact optimisation is achieved through a coarse- to-fine strategy with connections to adap- tive rejection sampling. We perform ex- act optimisation with unpruned language models of order 3 to 5 and show search- error curves for beam search and cube pruning on standard test sets. This is the first work to tractably tackle exact opti- misation with language models of orders higher than 3.