Dynamic thesaurus construction from english-japanese dictionary

We propose a method that constructs a hierarchy of words from a set of given documents automatically and dynamically. Given a query, the system retrieves the set of documents that satisfy the query, and the related words are extracted automatically, according their document frequencies. Then a hypernym relations of these related words are obtained using co-occurrence frequencies. Empirical evaluation are conducted for the word hierarchy derived from an English-Japanese dictionary, where the descriptions of a word is considered as one documents. It is shown that meaningful structures are obtained. It is also shown that the proposed method generates more fine hierarchy compared to that obtained by Niwa's and Srinivasan's method.