Experiences in reusing knowledge sources using Protégé and PROMPT

We study the general question of how ontologies and reference terminologies can be used to make development of knowledge bases more manageable, taking into account the methodologies and tools available nowadays. For this, we have carried out a case study on designing a knowledge base oriented to support a diagnosis-aid application in ophthalmology. Ideally, starting from a pre-existing domain ontology, development of knowledge bases is centred only on collecting specific knowledge for a particular application. In practice, this is a very time-consuming approach, as ontology repositories do not usually provide many information-seeking facilities. In addition, it is unlikely to find an ontology that includes all the required knowledge. Consequently, design of knowledge bases requires the combination and adaptation of one or more source ontologies. In this work, particular attention is paid to the proper merging of two ontologies using the tool PROMPT. Our study emphasizes the advantages of using PROMPT for merging ontologies containing closely related portions of knowledge, as well as some proposals for improvement. In a second step, our approach extends the evolving ontology, with a new component that holds both a meta-model representing a very simplified structure of a terminology system into Protégé-2000 and a set of constraints expressed using the Protégé Axiom Language. This set of constraints allows us to check the consistency and coherence of the imported information. Defining meta-classes in Protégé-2000 links this component to the rest of the models in the knowledge base. We report our experience in the reuse of several knowledge sources using Protégé-2000 and several of the plug-ins.