Hierarchy extraction based on inclusion of appearance

In this paper, we propose a method of auto-matically 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 devel-oped for the recognition of degraded machine-printed 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 co-occurring with adjectives in Japanese and compare with hierarchies in the EDR elec-tronic dictionary.