In philosophy, ontology describes a branch of metaphysics concerned with the nature and relations of being. The term has been redefined by the knowledge engineering and artificial intelligence communities to refer to a formalised description of the concepts and relationships that exist within a specific domain and all that can be represented about that domain. Ontologies can be mental models, computer models, or a combination of both. Ontologies provide a means by which characteristics of a specific representation can be assumed and behaviour predefined (Kemp & Vckovski 1998) . Multiple user views can be accommodated by providing translations between different ontologies.