Using the WordNet Concept Catalog and a Relation Hierarchy for Knowledge Acquisition

In order to guide a knowledge engineer in the design of ontologies, CGKAT (Martin, 1995), our knowledge acquisition tool, exploits the terminological knowledge base WordNet. Since the top-level concept types of this large general ontology are poorly structured, we subordinated/merged them into an extension of the top-level ontology adviced by Sowa (1992). The result is proposed in the initial concept type lattice of CGKAT. Since WordNet is an on-line system, only the WordNet top-level concept types need to be included in the lattice: CGKAT enables the user to search the WordNet ontology by browsing or lexical search, and dynamically places the retrieved concept types in the lattice. Any part of the lattice may be reorganized without loosing access to the WordNet ontology. Thus, only the WordNet part that is useful for an application has to be definitely included in the lattice. This part, which is very detailed, eases interpretation, validation, reuse and automatic inferences on knowledge of the application. In this article, we detail the mechanism of dynamic inclusion of the WordNet ontology in the lattice, and its interests for knowledge representation and reuse, and we give the rationales behind our top-level ontology. Lastly, we sum up the interests of the use of basic relations for KA (in (Martin, 1995) we have already presented a top-level ontology for 200 basic relation types gathered from the hypertext and knowledge representation literature).