Using our notation, for a policy g(•), the per-step CW at step t is CW g (t) = g(t)−g(t−1).
the CW of a sentence-pair (x, y) is the average CW over all consecutive wait segments: CW measures the average source segment length (the best case is 1 for wordby-word translation or our wait-1 and the worst case is |x| for full-sentence Mt).