Evaluating Chinese-Vietnamese Low-resource Machine Translation with Back Translation
Table 2: Results of character-based SMT
['Directions Settings', 'zh\\rightarrowvi BLEU', 'zh\\rightarrowvi METEOR', 'vi\\rightarrowzh BLEU', 'vi\\rightarrowzh METEOR']
Under each same size of synthetic data, most of scores of Vietnamese data are higher than those of Chinese, and the trend of scores is also relatively stable. However, in the opposite translation direction, strangely, synthetic data have significant negative impacts on the performance, with the adding of data size, most of BLEU scores have been declining, most of them are even lower than the baseline (16.73). When comparing the two directions, BLEU scores of vi\rightarrowzh are generally about2 points higher than those of zh\rightarrowvi.