The Process of Semantic Annotation of Web Services

Abstract

Web services are software components that are—in general—distributed over multiple organizations. They provide functionality without showing implementation details for the purpose of abstracting from implementation as well as for the purpose of hiding private, that is, organization-internal, processes. Nevertheless, to use a Web service one must know some of its details, that is, what it does, what it requires, what it assumes, what it achieves, and to some extent, how it achieves its purpose. The different Web service standards, frequently summarized as WS*, allow Web services to be specified with descriptions of such details. In this chapter, we argue that one should go beyond WS* and that it is preferable to provide semantic descriptions, that is, specifications that can be understood and correctly interpreted by machines. Thereby, the particular focus of this contribution lies in analyzing the process of semantic annotation, that is, the process of deriving semantic descriptions from lower level specifications, implementations and contextual descriptions. Hence, the concern of this chapter is really orthogonal to most other work which equates Web service annotation with Web service specification. We illustrate here that this is not the case.