Improving fast align by Reordering

fast align is a simple, fast, and effi-cient approach for word alignment based on the IBM model 2. fast align per-forms well for language pairs with rel-atively similar word orders; however, it does not perform well for language pairs with drastically different word orders. We propose a segmenting-reversing reorder-ing process to solve this problem by al-ternately applying fast align and re-ordering source sentences during train-ing. Experimental results with Japanese-English translation demonstrate that the proposed approach improves the per-formance of fast align significantly without the loss of efficiency. Experiments using other languages are also reported.