SAWSDL W3C Recommendation!

It will mostly go unnoticed, but last week (28 Aug 2007), the specification for Semantic Annotations for WSDL and XML Schema (SAWSDL) was published as a W3C Recommendation, as much of a Web standard as a standardization process can give you. I see SAWSDL as a stepping stone towards Web-friendly (and SemWeb-friendly) semantic web services.

A very short overview, adopted from the WG page (and slightly edited):

The SAWSDL Recommendation defines mechanisms using which semantic annotations can be added to WSDL components. SAWSDL does not specify a language for representing the semantic models; instead, it provides mechanisms by which concepts from the semantic models can be referenced from WSDL components as annotations. The semantics can help disambiguate the description of Web services during automatic discovery and composition of the Web services.

As its main contribution, SAWSDL defines the following three new extensibility attributes for WSDL 2.0 elements to enable semantic annotation:

  • an extension attribute named modelReference specifies the association between a WSDL component and a concept in some semantic model,
  • two extension attributes, named liftingSchemaMapping and loweringSchemaMapping, that are added to XML Schema for specifying mappings between semantic data and XML, to be used during service invocation or mediation.

The spec itself is very simple, but its implications are important. Previous Semantic Web Services (SWS) research has always started from a big semantic model (even framework) and tried to do everything, hiding WSDL in the "invocation details you don't wanna know" parts called grounding. With SAWSDL, WSDL becomes the central model and the frameworks can be broken down into small pieces that are then attached to it.

While SAWSDL may not change the end functionality of SWS, it makes it much more comprehensible to WSDL people learning about semantics. Instead of "here's our model, learn it!", the SWS people will now approach the WSDL people with "here are the bits that might help you in various ways in these new clever tools, and your normal tooling will just ignore them so there's no harm."

With a few colleagues, we're working on WSMO-Lite precisely along these lines, the only thing that we now need from W3C is a rule language (cf. RIF) to be able to do everything that WSMO does using no invented languages, just a few simple ontologies.

Anyway, this all is a big deal for me because I chaired the working group; it was a year of a lot of work, plenty of it very pleasant; I learned a lot and got to know some very cool people. And it's also a big deal for me because it's supposed to serve as the bridge between my old community (Web Services; I grew up in Systinet) and the new one, SWS research.

Posted at 1150 on Wed, Sep 5, 2007 in category Work | TrackBack | Comments feed
Post a comment

(will not be published)

Remember personal info?