Different applications can associate different meanings with similar or identical terms. Whereas humans can (usually) distinguish between different interpretations of either the information content or transaction intent, agents will only be able to act meaningfully if the content exchanged between them, and the services they provide, carry sufficient explicit information. In order to enable consistent behaviours amongst the (virtual) participants in a virtual market and to allow complex interactions such as mediation, greater levels of semantic content have to be made explicit and represented in a computer readable form. Shared ontologies have been identified as central issue for the development of open distributed environments.
An ontology is a formal explicit specification of an agreed standardised vocabulary, a precise definition of the basic terms and the relationships that can exist between them [Gru93]. An ontology may specify knowledge and information on various abstraction levels. The OntoBroker [DEMS99] uses formal ontologies to extract, reason, and generate meta-data in the WWW. Various organisations develop international standards for business processes, models or product descriptions to enable the integration of heterogeneous applications and human-users for specific business processes across the supply and production chain. For example, RosettaNet, a consortium of manufacturers, distributors, resellers, end users, and solution providers, devises a framework for business-to-business electronic data interchange over the Internet. Within the RosettaNet framework, a technical standard for a universal laptop has been developed (cf. [Ros98]). Ontologies which standardise certain behavioural aspects of business transactions are also being developed.
Ontologies in this extended SEAMLESS KRAFT architecture shall exist as axiomatisations of generic domain models. Axioms identify a basic set of abstract properties, characteristics and associations for the semantic description of services, products or generic processes. For example, generic domain models may exist in the form of formal specifications for devices and components, using constraint logic programs.