This talk

• Answer the key questions:
  • WHY are we doing this? (Intro to ontologies on the web)
  • WHO is taking part? (Makeup of the Working Group)
  • WHEN did we start and when might we end? (History and schedule)
  • WHAT have we done so far? (Results of WG to date)
  • WHERE are we spending our time? (Some open issues)

Ontologies

An ontology defines the terms used to describe and represent an area of knowledge. Ontologies are used by people, databases, and applications that need to share domain information (a domain is just a specific subject area or area of knowledge, like medicine, tool manufacturing, real estate, automobile repair, financial management, etc.). Ontologies include computer-usable definitions of basic concepts in the domain and the relationships among them ...
They encode knowledge in a domain and also knowledge that spans domains. In this way, they make that knowledge reusable.

Working Draft, Web Ontology Working Group.

Ontologies on the Web...

<daml:Class rdf:ID="WeatherEvent">
  <rdfs:comment>Superclass for all weather events
  <rdfs:label>Weather event
</daml:Class>

<daml:Class rdf:ID="WeatherReport">
 <rdfs:comment>Superclass for all handled weather reports</rdfs:comment>
 <rdfs:label>weather report</rdfs:label>
   <rdfs:subClassOf rdf:resource="#DatedWeatherEvent"/>
   <rdfs:subClassOf>
     <daml:Restriction daml:minCardinality="1">
       <daml:onProperty rdf:resource="#hasWeatherEvent"/>
     </daml:Restriction>
  </rdfs:subClassOf>
  <rdfs:subClassOf>
     <daml:Restriction daml:cardinality="1">
       <daml:onProperty rdf:resource="#hasStationID"/>
      </daml:Restriction>
  </rdfs:subClassOf>
  <rdfs:subClassOf>
     <daml:Restriction daml:cardinality="1">
        <daml:onProperty rdf:resource="#hasReportTime"/>
     </daml:Restriction>
  </rdfs:subClassOf>
  <rdfs:subClassOf>
    <daml:Restriction daml:cardinality="1">
    <daml:onProperty rdf:resource="#hasReportDate"/>
  </daml:Restriction>
  </rdfs:subClassOf>
  </daml:Class>

...Creating a Web of Ontologies

Using the web of Ontologies

• e.g. relate terms in different XML schemas, to...
• RDF schemas describing relational data, to...
• Web service descriptions.

A Brief History of Web Ontology Work

• Ontology work goes back many years in fields of philosophy, Library Science, Knowledge Rep.
• Ontology Aimed at the Web grew as research area in the 1990s.
  • 1995 - SHOE (Simple HTML Ontology Extensions), Univ of Md.
  • 1996/7 - Ontobroker, Univ. of Karlsruhe
  • 1997-1999 - OIL (Ontology Interchange Level), Amsterdam led EU project
• Spin-off from Govt Investment in Semantic Web Technology
  • 1999 - The DARPA Agent Markup Language Program
  • 2000 - EU IST Project (Framework 5, 6)
  • 2000 some US National Science Foundation funding
  • proposed - govt "jumpstart" activities in Japan and Australia
• Standardization Efforts
  • 1997 - W3C Metadata Activity (RDF Recommendation 1999)
  • 2000-03 - DAML 0.5 released
  • 2001-03 - DAML+OIL 1.0 spec developed by "US/EU ad hoc Joint Committee on Agent Markup Language"
  • 2002-11 - Web Ontology Working Group

The W3C Web Ontology Working Group

• The WOWG is working to create a recommendation for the "Web Ontology Language": OWL
• 51 Members from 30 W3C Organizations
  • Companies: Agfa, Daimler-Chrysler, EDS, Fujitsu, Hewlett-Packard, IBM, Intel, IVIS, Lucent, Network Inference, Nisus, Nokia, Philips, Stilo, Sun, Unisys
  • Public Sector: DISA, Electricite de France, Intelink, INTAP, MITRE, NIST
  • Research projects/Labs: DFKI, FZI, Ibrow group, Stanford, U. Bristol, U. Maryland, U. Southhampton
  • Invited Experts: Medical, Digital Library, Defense, Technical
• CoChairs: Jim Hendler, University of Maryland/MIND;
  Guus Schreiber, Univ of Amsterdam/Ibrow
• W3C Web Ontology WG

WOWG - Status and Schedule

• Nov. 2001 - WOWG start
• -> Jan 2002 (First Face to Face: Lucent)
  • Concentration on use cases; Mastery of DAML+OIL
  • Working Draft (Requirements) released 2002-03-07
• -> Apr 2002 - (Second Face to Face: CWI, Amsterdam)
  • Move to Issue-driven process
  • Issues List
• -> July 2002 - (3rd Face to Face: Fujitsu/Stanford U)
  • Goal: Release Working Draft - Language Core, Test cases, Model Theory, Guide
• -> Oct 2002 - (4th Face to face: Hewlett-Packard, UK)
  • Move through process and to proposed Rec.

WOWG: Identification of Use Cases

• Abstracted six categories of Use case from approx 25 real-world applications/prototypes
  • Web Portals
    • Categorization rules enhance search
  • Multimedia Collections
    • Content-based searches for non-text media
  • Corporate Web Site Management
    • Taxonomical Organization of documents
    • Mapping Between Corporate Sectors (mergers!)
  • Design Documentation
    • Explication of "derived" assemblies (e.g. wing spar)
    • Explicit Management of Constraints
  • Intelligent Agents
    • User Preferences/User Interests
    • Content Mapping
  • Ubiquitous Computing
    • Web Service Discovery and Composition
    • Rights Management and Access Control
    • Context-dependent content reformating
• Use Cases

WOWG: Requirements Working Draft - Goals

• Goals
  • Shared ontologies
  • Ontology evolution
  • Ontology interoperability
  • Inconsistency detection
  • Balance of expressivity and scalability
  • Ease of use
  • XML syntax
  • Internationalization

WOWG: Requirements Working Draft - Reqs/Obj

• WD Requirements: Identified 19 requirements (i.e. We WILL do these things)
  • Ontologies as distinct objects, Unambiguous term referencing with URIs, Explicit ontology extension, Commitment to ontologies, Ontology metadata, Versioning information, Class definition primitives, Property definition primitives, Data types, Class and property equivalence, Individual equivalence, Local unique names assumptions, Attaching information to statements, Classes as instances, Complex data types, Cardinality constraints, User-displayable labels, Supporting a character model, Supporting a uniqueness of Unicode strings.
• WD Objectives : Identified 7 objectives (we will try to do, but aren't sure we can)
  • Commitment to portions of ontologies, View mechanism, Integration of digital signatures, Arithmetic primitives, String manipulation, Aggregation and grouping, Procedural attachment

We welcome your comments at public-webont-comments@w3.org

WOWG Issues