You'll hear about

• Semantic Web Services
• W3C efforts in SWS
• Semantic Annotations for WSDL

Tasks common around Web Services

• Discovery
• Selection
• Composition
• Negotiation and contracting
• Invocation
• Monitoring
• Recovery from failure
  
  
• All of them done basically manually

Semantic Web Services

• Automating those tasks:
  
  
• Semantic description for discovery, composition
• Process description for composition, monitoring
• Non-functional properties, policies for selection, negotiation
• Grounding for invocation
  
  
• Using semantic technologies — Semantic Web Services
• Existing frameworks looking at solutions — WSMO, OWL-S, SWSL

Semantic Web Services efforts in W3C

• Workshop on frameworks for SWS — June 2005
• SemWebServices Interest Group and SAWSDL WG work on defining use cases
• SAWSDL provides hooks for semantics in WSDL
  • Based on WSDL-S
  • Covers semantic description, grounding
• Next steps to be defined

Semantic Annotations for WSDL

Model references

Point to semantic description of a WSDL component

Example: XML element <price> is an item price in US dollars

Example: operation add adds item to shopping basket

Schema mapping

Describes mapping of data between XML and semantic representation

Example: XML element <address> becomes an instance of OWL class Address, mapping the children appropriately

Interface category

Puts an interface into some taxonomy

Example: interface Printer falls among printing interfaces

Scope of SAWSDL

• Specify semantic annotations: model references, schema mapping, interface categorization
• Define the mapping to RDF (based on WSDL RDF mapping)
• Based on WSDL 2.0, back-ported to WSDL 1.1
  
  
• Out of scope: preconditions, effects, fully-fledged semantic framework

Working Group

• Started in April
• 18 official members (10 organizations)
• Talking with user companies for use cases
• Editors' drafts: SAWSDL, Use cases and examples
• Issues list — 15 issues, 10 open

Interesting issues

• 2: embedding semantic descriptions
  • as opposed to refering to external descriptions
• 3: identifying type of model
  • OWL, OWL-S, WSMO, SWSL?
  • leave it to the Web
• 5: multiple annotations on one component?

Timeline

• Jun 2006 — first face-to-face meeting, first public drafts
• Sep 2006 — last call for comments
• Dec 2006 — candidate recommendation
• Mar 2007 — recommendation

Summary

• First step towards Semantic Web Services
• For automation of Web Service-related tasks
• Light-weight annotations
• Constructive opinions on use cases welcome