Automatic Construction of Japanese WordNet

Although WordNets have been developed for a number of languages, no attempts to construct a Japanese WordNet have been known to exist. Taking this into account, we launched a project to automatically translate the Princeton WordNet into Japanese by a method of unsupervised word-sense disambiguation using bilingual comparable corpora. The method we propose aligns English word associations with those in Japanese and iteratively calculates a correlation matrix of Japanese translations of an English word versus its associated words. It then determines the Japanese translation for the English word in a synset by calculating scores for translation candidates according to the correlation matrix and the associated words appearing in the gloss appended to the synset. This method is not robust because a gloss only contains a few associated words. To overcome this difficulty, we extended the method so that it retrieves texts by using the gloss as a query and uses the retrieved texts as well as the gloss to calculate scores for translation candidates. A preliminary experiment using Wall Street Journal and Nihon Keizai Shimbun corpora demonstrated that the proposed method is promising for constructing a Japanese WordNet.