SMT decoder dissected: word reordering

We describe a decoder for statistical machine translation which allows controlled reordering of the words generated in the target language. After a general discussion of the structure of a decoder a particular implementation is discussed which allows for word-to-word and phrase-to-phrase translation. Word reordering is used to improve the translation quality. We analyze the effect of the length of this reordering window on the search space and the translation quality. Results for Chinese-to-English and Arabic-to-English translation tasks are presented.