Cohesive Constraints in A Beam Search Phrase-based Decoder

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. We show that the cohesion-enhanced decoder significantly outperforms the standard phrasebased decoder on English→Spanish. Improvements between 0.5 and 1.2 BLEU point are obtained on English→Iraqi system.