Automatic Construction of Clean Broad-Coverage Translation Lexicons

melamedunagicisupennedu Wordlevel translational equivalences can be extracted from parallel texts by surprisingly simple statistical techniques However these techniques are easily fooled by indirect associations pairs of unrelated words whose statistical properties resemble those of mutual translations Indirect associations pollute the resulting translation lexicons drastically reducing their precision This paper presents an iterative lexicon cleaning method On each iteration most of the remaining incor rect lexicon entries are ltered out without signicant degradation in recall This lexicon cleaning technique can produce translation lexicons with recall and preci sion both exceeding as well as dictionarysized translation lexicons that are over correct Translation lexicons are explicit representations of translational equivalence at the word level They are central to any machine translation system and play a vital role in other multilingual appl