2 Attempts to measure the impact of translation divergences in MT have focused on the introduction of noise in sentence alignments (Goutte et al., 2012), showing that statistical MT is highly robust to noise, and that performance only degrades seriously at very high noise levels.
neural MTs seem to be more sensitive to noise (Chen et al., 2016), as they tend to assign high probabilities to rare events (Hassan et al., 2018).