Abstract
This paper proposes a method for information extraction of hypernyms from dictionaries, and presents a result of automatic construction of word ontology based on the extracted information. The method recursively expands word definitions to get much larger word sets, which will be candidates of hypernyms of the headwords. At the same time, this method gives likelyhood of the candidates for hypernyms, which is useful for selecting hypernyms from the candidates. Computational experiments showed that the proposed method gives better results than an existing method, which regards HEAD as hypernyms by parsing the explanatory notes. Additionally, we tryed to create a word ontology with the resulting hypernyms. This method is still underconstruction, but the results showed effectiveness of the resulting hypernyms, and showed possibility of entirely automatic construction of word ontology.
