These findings illustrate the benefit of supervised training for alignment, suggesting further annotation of gold-standard alignments is warranted, with an emphasis on alignment quality.
5 Figure 3 indicates that labelled alignment data is far more valuable than bitext, meaning that efforts should be focused on annotating existing bitext for alignment; FastAlign's performance (when trained on the entire 4 million-sentence training bitext and the alignment bitext) can be surpassed after pretraining the translation model on only 400K sentences of unlabelled bitext and the full alignment set (4871 sentences).