Cohesive Constraints in A Beam Search Phrase-based Decoder

Abstract

Cohesive constraints allow the phrase-based decoder to employ arbitrary, non-syntactic phrases, and encourage it to translate those phrases in an order that respects the source dependency tree structure. We present extensions of the cohesive constraints, such as exhaustive interruption count and rich interruption check. Furthermore, we present analyses related to the impact of cohesive constraints across language pairs with different reordering models and dependency parsers. Our experiments show that the cohesion-enhanced decoder performs statistically significant better than the standard phrasebased decoder on English-Spanish. Improvements between 0.4 and 1.8 BLEU point are also obtained on English-Iraqi, Arabic-English and Chinese-English systems.

Publication
Proceedings of Human Language Technologies: The 2009 Annual Conference of the North American Chapter of the Association for Computational Linguistics, Companion Volume: Short Papers