Clause alignment for Hong Kong legal texts

In this paper we report on our recent work in clause alignment for English-Chinese bilingual legal texts using available lexical resources including a bilingual legal glossary and a bilingual dictionary, for the purpose of acquiring examples at various linguistic levels for example-based machine translation. We present our formulation of an appropriate measure for the similarity of a candidate pair of clauses with respect to matched lexical items and the corresponding implementation of an effective algorithm for clause alignment based on this similarity measure. Experimental results show that the similarity measure and the lexical-based clause alignment algorithm, though very simple, are very effective, with a performance of 94.6% alignment accuracy. It confirms our intuition that lexical information gives a reliable indication of correct alignment. The significance of this lexical-based approach lies in both its simplicity and effectiveness.