On Using Monolingual Corpora in Neural Machine Translation
Table 4: Results for De-En and Cs-En translation tasks on WMT’15 dataset.
['[EMPTY]', 'De-En Dev', 'De-En Test', 'Cs-En Dev', 'Cs-En Test']
Shallow fusion achieved 0.09 and 0.29 BLEU score improvements respectively on De-En and Cs-En over the baseline NMT model. With deep fusion the improvements of 0.39 and 0.47 BLEU score were observed again over the NMT baseline.