RDF

The educational technology and digital learning wiki
Jump to navigation Jump to search

Draft

Definition

  • The Resource Description Framework (RDF) is a language for representing information about resources in the World Wide Web.
  • Originally RDF was primarily intented to represent metadata about Web resources, such as the title, author, and modification date of a Web page, copyright and licensing information about a Web document, or the availability schedule for some shared resource. However, by generalizing the concept of a "Web resource", RDF can also be used to represent information about things that can be identified on the Web, i.e. the semantic web.

Major RDF vocabularies

Metadata
Content syndication and social software
  • RSS 1.0 which is not very popular, most RSS formats are not RDF since bloggers don't understand issues related to the semantic web :)
  • FOAF Friends-of-a-friend vocabulary for person networks
Semantic Web
  • OWL
  • SparQL (Query language)

RDF basics

At its core, RDF has a simple relational data model: Subject - Verb - Object or expressed differently Predicate (Subject, Object)

  • Sujet = The resource
  • Objet = Value
  • Verb = Predicate = propriety = relation of the subjet with the object

Here is a typical RDF fragment

<?xml version="1.0"?>
 <rdf:RDF xmlns:rdf="http://www.w3.org/1999/02/22-rdf-syntax-ns#"
          xmlns:mon_schema="http://tecfa.unige.ch/lib/mon_schema" >
 <rdf:Description rdf:about="http://tecfa.unige.ch/perso/staf/lattion/">
  <mon_schema:Creator>Stéphane Lattion</mon_schema:Creator>
 </rdf:Description>
</rdf:RDF>

It expresses a relation like this:

A simple ressource-author relationship


RDF and the semantic web

The RDF Software stack

The RDF software stack

The RDF bus

Software clients of the RDF bus


Links

Standards

Overviews

  • PICS (Platform for Internet Content Selection)

On-line validation

RDF-related web sites

Various to sort out

References

  • Eric Miller An Introductionto the Resource Description Framework (1998), D-Lib Magazine May 1998, ISSN 1082-9873, HTML