Patent ID: 7587307

Claim:
A method for computing machine translation performance, comprising: receiving a sequence of natural language data in a first language; translating the sequence of natural language data to a second language to define a machine translation of the sequence of natural language data comprising symbols; receiving a reference translation of the sequence of natural language data in the second language comprising symbols; with a computer processor, computing a sequence kernel that provides a similarity measure between the machine translation and the reference translation based on occurrences of subsequences that are shared by the machine translation and the reference translation, for a selected subsequence length, including performing an inner product in a feature space of all possible subsequences of a selected subsequence length; outputting a signal indicating the similarity measure; wherein the similarity measure accounts for non-contiguous occurrences of subsequences of the selected subsequence length that are shared between the machine translation and the reference translation, in which the non-contiguous subsequences share symbols and comprise a gap of at least one symbol which has been determined not to match a symbol in the gap of the other.