Improving machine translation by training against an automatic semantic frame based evaluation metric
Chi-kiu Lo, Karteek Addanki, Markus Saers, Dekai Wu · 2013
We present the first ever results show-ing that tuning a machine translation sys-tem against a semantic frame based ob-jective function, MEANT, produces more robustly adequate translations than tun-ing against BLEU or TER as measured across commonly used metrics and human subjective evaluation. Moreover, for in-formal web forum data, human evalua-tors preferredMEANT-tuned systems over BLEU- or TER-tuned systems by a sig-nificantly wider margin than that for for-mal newswire—even though automatic se-mantic parsing might be expected to fare worse on informal language. We argue that by preserving themeaning of the trans-lations as captured by semantic frames right in the training process, an MT sys-tem is constrained to make more accu-rate choices of both lexical and reorder-ing rules. As a result, MT systems tuned against semantic frame based MT evalu-ation metrics produce output that is more adequate. Tuning a machine translation system against a semantic frame based ob-jective function is independent of the trans-lation model paradigm, so, any transla-tion model can benefit from the semantic knowledge incorporated to improve trans-lation adequacy through our approach. 1