However, domain specific ontologies generally contains many "fine-grained" categories (e.g., particular categories of people, such as writers, scientists, and so on) and, as a consequence, supervised methods cannot be used because the annotation costs would become prohibitive.
in the literature, the fine-grained classification task has been approached by adopting weakly supervised (Tanev and Magnini, 2006;Fleischman and Hovy, 2002) or unsupervised methods (Cimiano and Völker, 2005).