1. Resource Description Framework
Presentation by Ray James
For Semantic Web
UT Austin, Spring 2006
Out of chaos, order
March 20, 2006

2. RDF overview What RDF is What RDF can do How to use RDF
Current RDF applications
RDF’s future
Summary & Sources
March 20, 2006

3. RDF basics Metadata is constructed information
Metadata is developed by people for a purpose or function
Metadata can be a surrogate
From Karen Coyle
March 20, 2006

4. What RDF is Key Definitions:
Resource Description Framework: An XML expression used to make simple assertions about relationships between things.
RDF Schema: A language used to describe the relationship between classes of things, or relationships between concepts in a particular domain.
March 20, 2006

5. In other words RDF defines a convention essential for the Semantic Web
RDF is machine and human readable but primarily for the machine
RDF is an infrastructure that enables the encoding, exchange, and reuse of structured metadata.*
* Eric Miller
March 20, 2006

6. What RDF is History dates just over a decade
Creation process began in 1990s; outgrowth of PICS
First RDF working draft October 1997
Semantic Web Activity & first RDF Interest Group meeting, February 2001
Collaborative design process
March 20, 2006

7. What RDF is Breaking down RDF
Anything can be a resource: Web page, PDA, document, etc. (identified with URI)
Description means how a resource is related to any other resource or object
Framework means ontological construct
Source:
March 20, 2006

8. Describing RDF
RDF promotes semantic interoperability; XML promotes syntactic interoperability.
Diagram from Dr. Miles Efron lecture notes.
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9. Describing RDF RDF is all about the “triples”
Resource, Property, Value Or
Subject, Predicate, Object
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10. RDF triples graphically
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11. More on RDF triples An Object can become Subject of new triple
‘Nesting’ of properties without limit
Triples concept maintained in RDF Schema
RDFS creates vocabularies
RDFS triples are: classes, class properties and (atomic) values
March 20, 2006

12. RDF graphically From: Explorer’s Guide to the Semantic Web
March 20, 2006

13. RDF in words
There is a person who is named William Sparks who has a telephone number and who has an address which is composed of an address (number and street) and a city and a state and who has an account which was opened on Aug. 1, 2001 and uses the address
Subject Predicate Object
Nested-subject Object
March 20, 2006

14. Reification
Reification describes the act of making a data model for a previously abstract concept.
Reification allows a computer to process an abstraction as if it were any other data
From Wikipedia
March 20, 2006

15. An RDF document <?xml version="1.0"?>
<rdf:RDF xmlns:rdf=" xmlns:dc="
<rdf:Description rdf:about="
<dc:title> Guidance on expressing the Dublin Core within the Resource Description Framework (RDF) </dc:title><dc:creator> Eric Miller </dc:creator><dc:subject> Dublin Core; Resource Description Framework; RDF; eXtensible Markup Language; XML </dc:subject><dc:publisher> Dublin Core Metadata Initiative </dc:publisher><dc:contributor> Dublin Core Data Model Working Group </dc:contributor><dc:date> </dc:date><dc:format> text/html </dc:format><dc:language> en </dc:language></rdf:Description> </rdf:RDF>
Adapted from
Subject Predicate Object
March 20, 2006

16. In words
There is a document declared in Dublin Core Schema found at the Dublin Core namespace (& RDF etc)
which has the title Guidance on expressing the Dublin Core within the Resource Description Framework (RDF) created by Eric Miller whose subject keywords are Dublin Core; Resource Description Framework; RDF; eXtensible Markup Language; XML published by Dublin Core Metadata Initiative contributed by Dublin Core Data Model Working Group on the date written in the format text/html and in the language en (English).
Subject Predicate Object
March 20, 2006

17. How RDF works All essential information is at: http://www.w3.org/RDF
Find RDF validator at the website:
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18. RDF applications
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19. RDF document <!-- /Creative Commons License -->
<!-- <rdf:RDF xmlns=" xmlns:dc=" xmlns:rdf=" <Work rdf:about=""> <dc:title>Metadata: Data with a Purpose</dc:title> <dc:date>2004</dc:date> <dc:description>A general discussion of document/resource metadata and some related uses.</dc:description> <dc:creator><Agent> <dc:title>Karen Coyle</dc:title> </Agent></dc:creator> <dc:rights><Agent> <dc:title>Karen Coyle</dc:title> </Agent></dc:rights> <dc:type rdf:resource=" /> <dc:source rdf:resource=" <license rdf:resource=" /> </Work> <License rdf:about=" <permits rdf:resource=" /> <permits rdf:resource=" /> <requires rdf:resource=" /> <requires rdf:resource=" /> <prohibits rdf:resource=" /> </License> </rdf:RDF>
March 20, 2006

20. RDF applications Mozilla: describes e-mail, news RSS: describes blogs
Annotea: describes Web pages
Dublin Core: describes meta data
Webscripter: defines and fuses
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21. RDF(S) creation applications
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22. More on Altova site
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23. RDF’s Future
Growing acceptance by Web site producers and users of metadata
Programs like SemanticWorks are positive signs that standard is healthy
Acceptance means use; use means continuing acceptance
Continued support (likely) from W3C
March 20, 2006

24. RDF Summary RDF … …is about relationships. …brings interoperability.
…is all about triples.
…can be found at
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25. Sources http://www.w3.org/RDF http://www.altova.com
OIL: An Ontology Infrastructure (Fensel and others)
An Introduction to the Resource Development Framework (Miller)
Explorer’s Guide to the Semantic Web (Passin)
Understanding Metadata and Its Purpose (Coyle)
March 20, 2006

26. Questions?
March 20, 2006