Attention Focusing for Neural Machine Translation by Bridging Source and Target Embeddings
Table 6: 1-gram BLEU scores averaged on test sets, supporting the assessment of under translation. A larger score indicates less under translation.
['[BOLD] System', '[BOLD] 1-gram BLEU']
While it is hard to obtain an accurate estimation of under translation, we simply report 1-gram BLEU score that measures how many words in the translation outcome appear in the reference translation, roughly indicating the proportion of source words that are translated. These data indicate that our improved system has a higher score than RNNSearch*, suggesting that it is less prone to under translation.