Fuzzification of a standard ontology to encourage reuse

A mapping between query terms and members of an ontology is usually a key part of any ontology enhanced searching tool. However many terms used in queries may be overloaded in terms of the ontology, which limits the potential use of automatic query expansion and refinement. In particular this problem affects information systems where different users are likely to expect different meanings for the same term. This paper describes the use of a "fuzzy ontology" which uses fuzzy relations between components of the ontology in order to preserve a common structure. The concept is presented in the medical domain, using a modification of the medical subject heading (MeSH) hierarchy. By adding a value for degree of membership to each relation for each user or group of users then the recovered documents from ontology mediated search can reflect the likely information need. This paper discusses the fuzzification scheme and its representation using XML.