Ontology Construction Toolkit

Abstract

The goal of this project was to enable knowledge engineers to construct knowledge bases (KBs) faster. To achieve this goal, we investigated two techniques: knowledge reuse and axiom templates. The results were demonstrated by developing a question-answering system for the crisis management challenge problem (CMCP). The solution of the CMCP required addressing problems broader than just knowledge reuse and axiom templates. The technical issues addressed in the process can be broadly classified into two categories: knowledge base content development and knowledge server development. We developed a geo-political KB for the CMCP. Specifically, we represented knowledge about international actions, terrorist groups, terrorist events, military capabilities, escalation and de-escalation of conflict, threats, and so forth. In the process of encoding the domain knowledge, we developed and adapted techniques for representing temporal knowledge and qualitative influences, and identified principles for taxonomy design. The knowledge server development focused on extending several of our existing tools. Our theorem prover SNARK (Stickel, Waldinger et al. June 1994) was extended to accept Knowledge Interchange Format (KIF) and a subset of the OKBC knowledge model (Chaudhri, Farquhar et al. 1998), to reason efficiently with Meta classes and temporal knowledge, and to produce explanations in HTML. We developed a worldwide web (WWW) interface to the GKB-Editor, which is a graphical tool for browsing and editing KBs. We developed tools for translating, loading, and saving ontologies encoded in a subset of KIF. The ontologies were loaded into Ocelot, which is a frame representation system developed at SRI. We extended our collaboration system to deal with schema changes and to synchronize the divergent copies of a KB. Instrumentation was developed to compute statistics on KB size, reuse, and axiom creation time.