A Comparative Study on Discontinuous Phrase Translation

Many research works have reported discontinuous phrase translation can significantly improve translation quality, but experiments are conducted in only one translation direction (e.g. Chinese-to-English) with only one language pair. Thus, two questions remain that whether the discontinuous rules are always much helpful in different language pairs? Furthermore, what kind of discontinuous rules (e.g. source-side discontinuity or target-side discontinuity) contributes most to the performance improvement? To answer these two questions, this paper conducts a comparative study on the contribution of different kinds of discontinuous rules in both translation directions with various language pairs. Then, with this comparative study, this paper proposes a role-based rule filtering strategy to filter the large amount of discontinuous rules that contribute very little to translation quality.