Hierarchy Extraction based on Inclusion of Appearance

In this paper, we propose a method of automatically extracting word hierarchies based on the inclusion relation of appearance patterns from corpora. We apply a complementary similarity measure to find a hierarchical word structure. This similarity measure was developed for the recognition of degraded machineprinted text in the field and can be applied to estimate one-to-many relations. Our purpose is to extract word hierarchies from corpora automatically. As the initial task, we attempt to extract hierarchies of abstract nouns cooccurring with adjectives in Japanese and compare with hierarchies in the EDR electronic dictionary.