Recent Semantic Web Services Standardization

• Semantic Annotations for Web Services Description Language (WSDL) —
  first Working Draft: http://www.w3.org/TR/2006/WD-sawsdl-20060630/
  (latest version: http://www.w3.org/TR/sawsdl/)
• RDF mapping for WSDL is in Last Call (ending 17 July).

Demonstrator Plan

• Influenced by the WP5 (Innsbruck) Workshop.
• Use semantic annotations of the Amazon Web Services description files.
• Give Semantic Web users the ability to query these (and other annotated) services.

SPDL Demonstrator

SPDL (SParql in wsDL) uses linkages between Web Services and the Semantic Web.

Demonstrate which technologies?

• Core W3C technologies: WSDL & SPARQL & XML Schema annotation.
• Semantic query of Web Services.

SPARQL + WSDL Demonstrator

Procedure:

• Identify the information in web services.
  • annotate existing descriptions
• Query that specific information.
• Automatically invoke the appropriate service(s).

Identifying information

• Popular languages are tailored to the consumer intuition.
• We chose SPARQL Annotations (SPARQL + XPath) in WSDL:
  • SPARQL: SQL-like RDF query language

    SELECT ?tile WHERE { ?response tnss:doctitle ?title }

  • XPath: identify locations in a document

    aws:ItemSearchResponse/aws:Items/aws:Item/aws:Title

  • WSDL: associate messages (documents) with services

    <definitions><types><element name="ItemSearchResponse"></element></types>...
        <message name="ItemSearchResponseMsg"/></definitions>

• SPARQL annotations tie RDF data to locations in a Web Services message.

  • <xs:element name="Item" spat:SPAT='?book tns:doctitle xpath("aws:Title")'/>
    

Demonstration

What happens when the user issues a query?

1. Machine matches a service to the query.
2. Invokes the service.
3. Returns results to RDF data model.
4. Data reported to user (or used in further queries).

Technology Features

• Minimal annotation —
  • tightest binding between Web Services data and Semantic Web data.
  • annotations uesful for many different purposes (discovery, invocation, orchestration)
• Reuse of existing technologies — no new languages or protocols, just recombinations.
• Actually able to do automatic invocation.

Relevance to Industry

• Lots of European participation in SAWSDL and the WP5 workshop.
• Investment from many vertical (biotech, pharma, financial) industries.
• Example industrial (B2B) useage:

  A chemical company offers a related-compound web service.
  A pharma company invokes complicated queries that transparently rely on related-compound.

Next steps

• Refine selection criteria.
• Demonstrate interesting orchestration.
  (orchestration done by SQL-like unification)

Next steps

• Refine selection criteria.
• Demonstrate interesting orchestration.
  (orchestration done by SQL-like unification)

Watch the SPDL Home Page for progress.

WP2 Extension Plan

The WS2 Extension Plan enables us to take the next steps:

We propose to extend this functionality with a proof-based matching algorithm. This will allow two new features, the deconstruction of user queries into smaller queries that can be answered by advertised services, and the selection of the best set of invocations to answer the user query. It is currently not known what criteria we will need to evaluate in order to weight alternative invocation paths. We will study existing web services such as the Amazon Web Services in order to establish practical criteria.

Demo excerpts

PREFIX tnss: <http://webservices.amazon.com/AWSECommerceService/2004-11-10>
SELECT ?asin ?title WHERE {
 ?X tnss:id "0FWYBWB91M5S26YBE382" ;
    tnss:keywords "cola" ;
    tnss:index "Books" ;

    tnss:asin ?asin ;
    tnss:doctitle ?title }

asin	title
"0896584542"	"The Sparkling Story of Coca-Cola"
"0953984028"	"The World Stormrider Guide (Stormrider Guides)"
"0887307515"	"Secret Formula"
"0873493818"	"The Encyclopedia of Pepsi-Cola Collectibles (Encyclopedia of Pepsi-Cola Collectibles)"
"0896960528"	"The Cola Wars: The story of the global battle between the Coca-Cola Company and PepsiCo, Inc."
"1887432930"	"Coca-Cola Collectible Santas (Collector's Guide to Coca Cola Items Series)"
"0977184307"	"Splenda® Is It Safe Or Not?"
"0873492412"	"Petretti's Coca-Cola Collectibles Price Guide (Petretti's Coca-Cola Collectibles Price Guide)"
"0553568914"	"Elvis, Jesus and Coca-Cola (Kinky Friedman Novels (Paperback))"
"0465054684"	"For God, Country, and Coca-Cola: The Definitive History of the Great American Soft Drink and the Company That Makes It"