2. The Resource Description Framework And its application to thegateway.org For the IIAP Jon Jablonski, jonjab@u.washington.edu Research Assistant The Information School University of Washington. May 18, 2001

3. Current work on theGateway Designing RDF based record structures Converting old data to RDF Establishing standards for expressing Dublin Core metadata

4. www.thegateway.org A consortial effort to provide a directory to quality educational materials on the web.

5. Behind the scenes: Content providers and consortium members catalog and embed metadata Register URIs with GEM Harvester crawls the metadata, builds database. GEM1 data is html meta tags. Descriptors based on Dublin Core + GEM qualifiers: www.geminfo.org/ Workbench/Metadata www.geminfo.org/ Workbench/Metadata

6. What is RDF? An evolving XML application. A model for representing metadata A syntax for encoding and transporting this metadata. A real-life beginning of the semantic web value of the property Stuff in the world property of stuff SubjectPredicateObject

7. So what does it look like? <rdf:Description rdf:about = "http://someplace.edu"> Really Interesting Subject Predicate Object And that is the entire model.

8. Dublin Core in RDF Expressing Dublin Core with RDF Eric Miller Dublin Core; RDF; XML Dublin Core Metadata Initiative Dublin Core Data Model Working Group 1999-07-01 text/html en

9. Structured entities Well, there are complications… Jon Jab jonjab@ u.wash.edu http://some_uri dc:creator gem:person gem:email

10. Same approach for Statements about Statements http://www.nytimes.com/learning/ Lesson Plan Archive

11. Schemas… …define classes and properties. Written in RDF Describes the relationships between properties and their resources. Analogous to ERDs. Can be used to control vocabulary. Core Classes rdfs:Resource rdf:Property rdfs:Class Core Properties rdf:type rdfs:subClassOf rdfs:subPropertyOf rdfs:seeAlso rdfs:isDefinedBy

12. Schemas declare standard compliance. Language Encoding Schemes A set of language encoding schemes and/or formats. RFC1766 Internet RFC 1766 'Tags for the identification of Language' specifies a two letter code taken from ISO 639, followed optionally by a two letter country code taken from ISO 3166. EN English A class Has subclasses. Which provide meaning for instances of data.

13. Schemas are also namespaces The GEM Element Set v2.0 The GEM Consortium The GEM metadata vocabulary is a simple vocabulary intended to facilitate discovery of educational resources. English 2001-03-16 Namespace declarations point to schemas Providing semantic meaning to entities.

14. Controlled language: values in RDF wordlists <gem:ERIC rdf:about="http://128.208.100.148/ thesauri/eric?Secondary_Education"> Secondary Education Thesaurus is one type of word list stored in rdf: programs schedules or plans of procedure under which a series of intended activities is directed toward desired results (note: use a more specific term if possbile)

15. Links rdf parser from w3.org http://www.w3.org/RDF/Implementations/SiRPAC/ rdf parser from w3.org RDF Model and Syntax Specification http://www.w3.org/TR/REC-rdf-syntax/ RDF Model and Syntax Specification RDF Schema Specification 1.0 http://www.w3.org/TR/2000/CR-rdf-schema-20000327/ RDF Schema Specification 1.0 RDF homepage http://www.w3c.org/RDF RDF homepage Expressing Qualified Dublin Core in RDF http://www.mathematik.uni-osnabrueck.de/projects/dcqual/qual21.3.1/qual21-3-1.html Expressing Qualified Dublin Core in RDF The Gateway to Educational Materials http://www.thegateway.org/ The Gateway to Educational Materials GEMinfo (about the Gateway) http://www.geminfo.org/ GEMinfo (about the Gateway)