Patent ID: 8825466

Claim:
A method for generating a tree to string annotated bilingual segment pair, the method comprising: receiving a first annotated bilingual segment pair comprising two or more words in a source language, two or more words in a target language, and an alignment between the two or more words in the source language and the two or more words in the target language; processing, by a computer, the first annotated bilingual segment pair to generate a target forest including a plurality of trees, each tree representing an alternative annotated bilingual segment pair including an alignment rule sequence that can be used to express a relationship between the words in the bilingual segment pair, the processing of the first annotated bilingual segment pair by the computer including re-labeling, re-structuring, and re-aligning the first annotated bilingual segment pair; building a derivation forest from the target forest, the derivation forest including a plurality of trees; deriving, by the computer, a plurality of rule sequences for the plurality of trees in the derivation forest, each tree in the derivation forest including a set of rule sequences derived from a tree in the target forest; selecting one of the derived rule sequences based on a probability that the selected rule sequence is more likely than the other derived rule sequences, using an expectation-maximization algorithm; generating, by the computer, a second annotated bilingual segment pair based on the selected rule sequence, wherein the second annotated bilingual segment pair has an alignment; and extracting translation rules from the second annotated bilingual segment pair based on the alignment of the second annotated bilingual segment pair.