Iterative Alignment of Syntactic Structures for a Bilingual Corpus

Abstract

Alignment of parallel bilingual corpora at the level of syntactic structure holds the promise of being able to discover detailed bilingual structural correspondences automatically. This paper describes a procedure for the alignment of regularized syntactic structures, proceeding bottom-up through the trees. It makes use of information about possible lexical correspondences, from a bilingual dictionary, to generate initial candidate alignments. We consider in particular how much dictionary coverage is needed for the alignment process, and how the alignment can be iteratively improved by having an initial alignment generate additional lexical correspondences for the dictionary, and then using this augmented dictionary for subsequent alignment passes1.