We argue that MBR-based methods in their present form are not well-suited for NMT because of the following reasons: • Previous approaches work well with rich lattices and diverse hypotheses.
(2008) has the form where Y h is the hypothesis space of possible translations, Y e is the evidence space for computing the Bayes-risk, and N is the set of all n-grams in Y e (typically, n = 1 .