The Resource Description Framework

And its application to thegateway.org

Where we’ll go…

Brief tour of thegateway.orgCurrent state of the project GEMcat 4.0GEM2RDF

www.thegateway.org

A really big experiment in self-cataloging.

A consortial effort to provide a directory to quality educational materials on the web.

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

Next steps:

Implement z39.50Blue Angel

Implement new data formatRDF

Release new cataloging moduleGEMcat 4?

What is RDF?

A model for representing metadataA syntax for encoding and transporting this

metadata.

value of the propertyStuff in the world

property of stuff

Subject Predicate Object

So what does it look like?

<rdf:Description

rdf:about = "http://someplace.edu">

<interest_level>

Really Interesting

</interest_level>

</rdf:Description>

Subject

Predicate

Object

And that is the entire model.

Dublin Core in RDF<rdf:Description rdf:about="http://some_URI”>

<dc:title>Expressing Dublin Core with RDF</dc:title>

<dc:creator> Eric Miller </dc:creator> <dc:subject> Dublin Core; RDF; XML </dc:subject>

<dc:publisher> Dublin Core Metadata Initiative </dc:publisher>

<dc:contributor>Dublin Core Data Model Working Group </dc:contributor>

<dc:date> 1999-07-01 </dc:date>

<dc:format> text/html </dc:format> <dc:language> en </dc:language> </rdf:Description>

Structured entities

Well, there are complications…

<rdf:Description rdf:about = "http://some_uri">

<dc:creator>

<rdf:Description>

<gem:person value="Jon Jab" />

<gem:email value="jonjab@u.wash.edu" />

</rdf:Description>

</dc:creator>

</rdf:Description>

Jon Jabjonjab@

u.wash.edu

http://some_uri

dc:creator

gem:persongem:email

Same approach for Statements about Statements

<dc:relation>

<gem:isChildOf>

<rdf:value>

http://www.nytimes.com/learning/

</rdf:value>

<rdfs:label>

Lesson Plan Archive

</rdfs:label>

</gem:isChildOf>

</dc:relation>

Controlled language & encoding schemes

<rdf:Description rdf:about="s3">

<gem:ERIC rdf:about="http://128.208.100.148/ thesauri/eric?Secondary_Education">

<rdf:value>Secondary Education</rdf:value>

</gem:ERIC>

</rdf:Description>

<gem:recordcreated>

<gem:iso8601_1988>

<rdf:value>1999-09-02T13:35:29-5:00</rdf:value>

</gem:iso8601_1988>

</gem:recordcreated>

Eventually, things get silly…

Links

rdf parser from w3.org RDF Model and Syntax Specification RDF Schema Specification 1.0 RDF homepage Expressing Qualified Dublin Core in RDF The Gateway to Educational Materials GEMinfo (about the Gateway)

This presentation: www.whatsgrowing.com/jon/docs/asis_rdf.ppt