For example, since the hypothesis translation from Table 1 has a length of 18 with 15 unigram matches, 10 bigram matches, 5 trigram matches, and three 4-gram matches, we can artificially construct an identically scored hypothesis by drawing an identical number of matching ngrams from the reference translations.
the manual evaluation conducted for the NISt Mt Eval is done by English speakers without reference to the original Arabic or Chinese documents.