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Wednesday, August 29, 2007

W3C Publishes Semantic Annotations for WSDL and XML Schema

The World Wide Web Consortium announced the publication of the
"Semantic Annotations for WSDL and XML Schema" specification as a W3C
Recommendation, together with a Usage Guide document, an Implementation
Report, and a Test Suite. The specification was produced by members of
the W3C Semantic Annotations for WSDL (SAWSDL) Working Group. The Usage
Guide presents examples illustrating how to associate semantic
annotations with a Web service; these annotations can be used for
classifying, discovering, matching, composing, and invoking Web services.
The Recommendation builds upon technology described in W3C Member
Submission "W3C Web Service Semantics - WSDL-S", contributed to W3C
by the University of Georgia Research Foundation and International
Business Machines Corporation, published 07-November-2005. Semantic
Annotations for WSDL and XML Schema defines how to add semantic
annotations to various parts of a WSDL document such as input and
output message structures, interfaces and operations. Specifically,
it defines a set of extension attributes for the Web Services
Description Language and XML Schema definition language that allows
description of additional semantics of WSDL components. A 'semantic
annotation' in this context is "additional information that identifies
or defines a concept in a semantic model in order to describe part of
that document. In SAWSDL, semantic annotations are XML attributes added
to a WSDL or associated XML Schema document, at the XML element they
describe. Semantic annotations are of two kinds: explicit identifiers
of concepts, or identifiers of mappings from WSDL to concepts or vice
versa. A 'concept' must be identifiable by URIs. A concept can be, for
example, a classifier in some language, a predicate logic relation,
the value of the property of an ontology instance, some object instance
or set of related instances, an axiom, etc." The specification defines
how semantic annotation is accomplished using references to semantic
models, e.g., ontologies. A 'semantic model' is a set of
machine-interpretable representations used to model an area of
knowledge or some part of the world, including software. Examples of
such models are ontologies that embody some community agreement,
logic-based representations, etc. Depending upon the framework or
language used for modelling, different terminologies exist for denoting
the building blocks of semantic models. CHECK HERE

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