Two aspects of the validation and verification of knowledge-based systems

Two research projects that have examined problems related to system verification and validation and the associated issue of maintenance are described. The Mekas (Methodology for Knowledge Analysis) Project has developed a method to give knowledge engineers a thorough characterization of the domain, that is, a full description of the ontology, structure, functions, and theories that underpin the domain. This provides a coherent framework within which a knowledge base can be more readily identified with key aspects of the domain, aiding verification and validation. The second project, known as MAKE (Maintenance Assistance for Knowledge Engineers), was aimed at the process of constructing and revising the knowledge base. It is argued that the primary focus of verification and validation must be on the models, and the transitions between them, rather than simply on the executable representation.<>