Resource Description Framework (RDF) Course: Electronic Document Team member: Ding Feng

1. Resource Description Framework (RDF) Course: Electronic Document Team member: Ding Feng Ding Wei Wang Ling Date:02.05.2002

2. Outline Introduction Benefits How RDF works? RDF characteristics RDF Model RDF Schemas Describing things with RDF History

3. Machine-understandable information Properties of WWW resources A framework for describing and interchanging metadata resource property statement RDF statements specify the properties and values of Web resources RDF is encoded in XML RDF Vocabularies Why Not Just Use XML Introduction

4. By providing a consistent framework, RDF will encourage the providing of metadata about Internet resources. Because RDF will include a standard syntax for describing and querying data, software that exploits metadata will be easier and faster to produce. The standard syntax and query capability will allow applications to exchange information more easily. Searchers will get more precise results from searching, based on metadata rather than on indexes derived from full text gathering. Intelligent software agents will have more precise data to work with. Benefits

5. a formal W3C Recommendation part of an Extensible Markup Language (XML) section constitute a class of such like descriptions classes could fit into a schema or hierarchy of classes The schema of classes proposal would save having to repeat descriptions since a single reference to the class of which a particular RDF description was a part would suffice The scheme or description of the collection of classes could itself be written in RDF language. How RDF works?

6. Independence Interchange Scalability Properties are Resources Values Can Be Resources Statements Can Be Resources Characteristics

7. A model is a set of statements Statement: = (predicate, subject, object) Predicate is a property Subject is a resource Object is value Object = Predicate(Subject) RDF Data Model

8. RDF Statements predicate Subject Object

9. RDF Statements <rdf:Statement> <rdf:subjectresource=“http://www.openhealth.org/RDF/rdfExtractify.xsl”> <rdf:predicate resource=“http://www.purl.org/dublin-core#author”> <rdf:object>Jonathan Borden</rdf:object> </rdf:Statement>

10. <rdf:Description about=“http://www.openhealth.org/RDF/rdfExtractify.xsl”> <dc:author>Jonathan Borden</dc:author> <dc:description>An XSLT based parser which converts an arbitrary XML document into RDF Statements</dc:description> </rdf:Description> Describing things with RDF

11. Describe rules for using RDF properties Are expressed in RDF Provides information about the interpretation of the statements given in an RDF data model Are not to be confused with XML Schemas (eventual DTD replacements) RDF Schemas

12. Simplified Schema <rdfs:Class rdf:ID=“Provider”> <rdfs:subClassOf rdf:resource=“#Person”/> </rdfs:Class>

13. May 2001: WWW10 W3C's Semantic Web Track and the Semantic Web Developers Day. Hong Kong Feb 2001: RDF Interest Group meeting (26-27 Feb 2001) Feb 2001: Semantic Web Activity launched Oct 1999: "Cambridge Communiqué" W3C NOTE issued on application schema layering Sep 2000XML World 2000 talk: XML and the Web. Mar 2000: RDF Schema Specification 1.0 published as a W3C Candidate Recommendation ( call for implementation) Aug 1999: RDF Interest Group created Feb 1999: RDF Model and Syntax Specification released as a W3C Recommendation (press release) May 1998RDF - Using XML to describe Data, Swick, WWW8 presentation April 1998WWW7 Tutorial, Using Web Metadata: Dublin Core and the Resource Description Framework, Lagoze, Miller, Lassila, Swick, Iannella, Schloss, Weibel Dec 1997W3C Metadata Activity Statement presented to the W3C Membership Nov 1997Introduction to RDF Metadata, W3C NOTE 1997-11-13, Ora Lassila Oct 1997first RDF working draft released History