Simple Fusion: Return of the Language Model
Table 4: Comparison of our PreNorm and PostNorm combination strategies with shallow fusion (Gulcehre et al., 2015) and cold fusion (Sriram et al., 2017) under an RNN-LM.
['[BOLD] Xhosa-English (Internal)  [BOLD] Method', '[BOLD] Xhosa-English (Internal)  [BOLD] Single', '[BOLD] Xhosa-English (Internal)  [BOLD] Single', '[BOLD] Xhosa-English (Internal)  [BOLD] 4-Ensemble', '[BOLD] Xhosa-English (Internal)  [BOLD] 4-Ensemble']
Tab. Shallow fusion (Sec. For our machine translation experiments we report mixed results with cold fusion, with performance ranging between 0.33 BLEU gain on Xhosa-English and slight BLEU degradation in most of our Turkish-English experiments.