A Knowledge Representation Formalism to Process Vague Medical Queries

Many fields of application deal with vague and fuzzy information. Thus the need of tools that are able to handle this kind of data is obvious. We concentrate on the extension of well-known terminological knowledge representation systems with appropriate methods. Classical terminological knowledge representation systems are based on two-valued logics. To solve problems of uncertainty a more expressive form is unalterable. A possible extension of these systems is given by multi-valued logics. This article provides a first introduction into knowledge representation with vague information. A language that is based on a special kind of multi-valued logic is introduced. The underlying logic is called fuzzy logic. Furthermore two domains that require the sort of described methods are sketched. Both domains give examples for relevant medical problems in connection with computer science.