A. Th. Schreiber

Using explicit ontologies in KBS development

Abstract This article presents a number of ways in which ontologies-schematic descriptions of the contents of domain knowledge-can be constructed and can be used to improve the knowledge engineering process. The main message is that early in the knowledge engineering process an application-specific ontology should be constructed. To facilitate this, the article presents some principles for organizing a library of reusable ontological theories which can be configured into an application ontology. This application ontology is then exploited to organize the knowledge acquisition process and to support computational design. The process is illustrated with a knowledge engineering scenario in the domain of treating acute radiation syndrome.

KADS: a modelling approach to knowledge engineering

Abstract This paper discusses the KADs approach to knowledge engineering. In KADS, the development of a knowledge-based system (KBS) is viewed as a modelling activity. A KBS is not a container filled with knowledge extracted from an expert, but an operational model that exhibits some desired behaviour that can be observed in terms of real-world phenomena. Five basic principles underlying the KADS approach are discussed, namely (i) the introduction of partial models as a means to cope with the complexity of the knowledge engineering process, (ii) the KADS four-layer framework for modelling the required expertise, (iii) the re-usability of generic model components as templates supporting top-down knowledge acquisition, (iv) the process of differentiating simple models into more complex ones and (v) the importance of structure—preserving transformation of models of expertise into design and implementation. The actual activities that a knowledge engineer has to undertake are briefly discussed. We compare the KADS approach to related approaches and discuss experiences and future developments. The approach is illustrated throughout the paper with examples in the domain of troubleshooting audio equipment.

From thesaurus to ontology

Thesauri such as the Art and Architecture Thesaurus (AAT) provide structured vocabularies for describing art objects. However, if we want to create a knowledge-rich description of an (image of an) art object, such as required by the semantic web, thesauri turn out to provide only part of the knowledge needed. In this paper we look at problems related to capturing background knowledge for art resources. We describe a case study in which we attempt to construct an ontology for a subset of art-object descriptions, namely antique furniture, using AAT as well as metadata standards as input. We discuss the representation requirements for such an ontology as well as representational problems for our sample ontology with respect to the emerging web standards for knowledge representation (RDF, RDFS, OIL).

Editorial: the Sisyphus-VT initiative

Abstract This special issue contains results of the second “Sisyphus ” study carried out in the knowledge acquisition community in the period 1992–1995. The Sisyphus initiative arose at the 1990 European Knowledge Acquisition Workshop in Driebergen (The Netherlands). To explain the rationale behind this initiative it is necessary to give a brief synopsis of the recent history of the knowledge-engineering field.

Architectures for intelligent systems based on reusable components

Given the dramatic growth of medical information and knowledge, one would expect there to be enormous demand for computer systems that aid in managing this information. Even if such systems are imperfect, they still should be used. Many of us, for example, complain about the deficiencies of our word processors, yet we continue to use them routinely anyway. Why, then, are so few people clamoring for the decision-support software that the medical-informatics community has been building? This seeming paradox is at the center of many ongoing debates. Heathfield and Wyatt [7] suggest that software developers are not giving sufficient attention to practical issues, such as whether users actually benefit from a system. At the same time, the need for better organizational analysis has been emphasized by researchers concerned with the integration of technology within the workplace [lo]. Heathfield and Wyatt also argue that there is a need for sound development methodologies for decision-support systems. Indeed, the literature describes countless systems that have been built in an ad hoc fashion without clear theoretical underpinnings. It is our contention that the lack of principled development strategies seriously hampers evaluation and maintenance of our systems, and leads to curtailed system life cycles. It is not sufficient, however, to argue simply for more principled approaches to software development. The question remains: On what principles should a viable

A competence theory approach to problem solving method construction

This paper presents a theory of the construction process of problem-solving methods (PSMs) on the basis of the competence theory approach. This approach describes the refinement process of an initial, abstract formalization of the required competence of a PSM, towards an operational version of the PSM. Three major steps in this process are identified: specification of the required competence theory, refinement of the theory into a form that fits a PSM paradigm and the operationalization of the theory into a form that is close to an executable specification. As an example, the ontological commitments and assumptions underlying some problem-solving methods for classification problems are investigated and their operational forms are presented.

Roles are not classes: a reply to Nicola Guarino

Abstract In this paper we reply to Nicola Guarinos comments on our article entitled “Using explicit ontologies in knowledge acquisition”. We concentrate on the issues raised by Guarino: (i) the existence of the interaction problem at the knowledge level, (ii) the nature of ontologies, and (iii) the utility of method ontologies. In our reply we attempt to distinguish between (mutual) misunderstandings, alternative viewpoints and true differences of opinion.

Sisyphus-VT: a CommonKADS solution

This article represents a CommonKADS contribution to the Sisyphus-VT experiment. This experiment is concerned with a comparison of knowledge modelling approaches. The data set for this experiment describes the knowledge for designing an elevator system. The ultimate goal is to arrive at standards for sharing and reusing problem-solving methods and related ontologies.

Applying KADS to the office assignment domain

Abstract In this article the KADS approach is used to model and implement the office assignment problem. We discuss both the final products (the model of expertise and the design) and the process that led to these products. Emphasis is put on modelling the problem in such a way that it closely corresponds to the behaviour of the expert in the sample protocol. The last section of the paper addresses the evaluation points raised by the initiators of Sisyphus.

Adapting Tableaux for Classification

We present an approach for studying logical properties of problem-solving methods (PSMs) for knowledge-intensive tasks. It is based on semantic tableaux (a deduction-style theorem-proving technique). We show how tableaux can be manipulated in a methodical way to formalize non-deductive style PSMs.