As the set of available Web Services expands, it becomes increasingly important to have automated tools to help identify services that match a requester's requirements. Finding suitable Web services depends on the facilities available for service providers to describe the capabilities of their services and for service requesters to describe their requirements in an unambiguous and ideally, machine-interpretable form. Adding semantics to represent the requirements and capabilities of Web services is essential for achieving this unambiguity and
We recommend that certain principles guide any work to define a framework for Web services semantics. Our work is guided by the following principles.
? Build on existing Web Services standards: The Web services standards are fast becoming a preferred technology for application integration because of the promise of their interoperability. Companies are making investments in integration projects based on Web Services. Therefore, we believe that any approach to adding semantics to Web Services should be specified in an upwardly compatible
Introduction
The Web Services Description Language (WSDL) specifies a way to describe the abstract functionalities of a service and concretely how and where to invoke it. The WSDL 2.0 specification does not include semantics in the description of Web services. Therefore, two services can have similar descriptions while meaning totally different things. Resolving this ambiguity in Web services descriptions is an important step toward automating the discovery and composition of Web services — a key productivity enabler in many domains including