Verification Of Knowledge-based Systems Research Articles

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. >

Interactive verification of knowledge-based systems

The Validator program, which interactively checks the consistency and completeness of a knowledge base, is discussed. Validator verifies and validates rule-based expert systems and guarantees that every element in the knowledge base is accessible and essential to the system. The program checks for syntactic errors, unused rules, facts, and questions, incorrectly used legal values, redundant constructs, rules that use illegal values, wrong instantiations, and multiple methods for obtaining values for expressions.< <ETX xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">&gt;</ETX>

EUROVAV-93: European Symposium on Validation and Verification of Knowledge-Based Systems

EUROVAV-93: European Symposium on Validation and Verification of Knowledge-Based Systems

An approach to the dynamic verification of knowledge-based systems

This paper describes a method of formal dynamic verification of knowledge-based systems. Almost all verification methods that have been proposed can validate the structural and logical integrity of knowledge-based systems, but they are not semantic. In other words, they are all static and syntactic. In addition, this paper adopts a dynamic approach in which verification is carried out in the reasoning process. This methid enables the detection of incorrect rules in the knowledge base using a simple debugging technique, which traces the execution of inference. Following the debugging algorithm, the user is asked several questions. To reduce the number of questions, knowledge is added to the system. In this way, some of the checks for correctness can be done by the system. Specifications are the judgement criteria of correctness, which are made up of some constraints. Application of the method to a power system operation is given. Benefits of this approach include: the ability to evaluate system's conclusions in situations where the experts may judge reasoning process, and the ability to predict the performance of the knowledge-based system in untested cases or to identify other cases that should be tested.