This slideshare belongs to a technology primer on OWL/RDF, produced by Csaba Veres (Bergen University, Norway) for the SESAM4 project.

1. A guide to semantics in the Linked Open Data cloud:
RDF and OWL
NFR Verdikt Project no 2342453 Semantic Technology
Technology Primer SESAM4 Consortium 2009 – 2011
SESAM4 2011 Published under Creative Commons license

2. What are RDF and OWL?
 RDF: Resource Description Framework
 Resource - Any piece of data you can put on the Web
 Description - Relationships between the Data
 A Data Model
 OWL: Web Ontology Language
 More Complex descriptions of Data
 Reasoning and Search
Technology Primer SESAM4 Consortium 2009 – 2011
SESAM4 2011 Published under Creative Commons license

3. Why a Data Model?
• Data models are not new
Name Address Telephone
John Smith 2 Nowhere place 111 222 333 Person
First Name
Henry Frod 15 Upmarket drive 123 456 789
Second Name
Residence
Person Contact
Name
Address
Telephone First Name Second Name Residence Contact
John Smith 2 Nowhere place 111 222 333
Henry Frod 15 Upmarket drive 123 456 789
Technology Primer SESAM4 Consortium 2009 – 2011
SESAM4 2011 Published under Creative Commons license

4. Why a Data Model for the Web?
Name Address Telephone
+
John Smith 2 Nowhere place111 222 333
Henry Frod 15 Upmarket drive 456 789
123
First Name Second Name Residence Contact
Jane Smith 2 Nowhere place 111 222 333
Henrietta Frod 15 Upmarket drivehnri@frod.com
= ???
Name Residence Telephone Email
Jane Smith 2 Nowhere place 111 222 333
Henrietta Frod 15 Upmarket drive hnri@frod.com
John Smith 2 Nowhere place 111 222 333
Henri Frod 15 Upmarket drive 123 456 789
Technology Primer SESAM4 Consortium 2009 – 2011
SESAM4 2011 Published under Creative Commons license

5. Identify Resources in Web Space
 How many houses does John Smith have?
 John Smith at 2 Nowhere place
 John Smith at 47 Hope street
 Does he have two houses, or two different people?
 URI
 General form of URL
 Every entity gets one
 http://www.example.org/person#js1
 http://www.example.org/person#js2
Technology Primer SESAM4 Consortium 2009 – 2011
SESAM4 2011 Published under Creative Commons license

6. What do we know about John Smith?
 We know
 http://www.example.org/person#js1
 has name “John Smith”
 has address “2 Nowhere place”
 has phone number “111 222 333”
 http://www.example.org/person#js2
 has name “John Smith”
 has address “47 Hope street”
 has phone number “333 222 111”
Technology Primer SESAM4 Consortium 2009 – 2011
SESAM4 2011 Published under Creative Commons license

7. Some RDF
@ prefix person <http://www.example.org/person#> .
@ prefix property <http://www.example.org/property#> .
person:js1 property:hasName “John Smith” ;
property:hasAddress “2 Nowhere place” ;
property:hasPhone “111 222 333” .
person:js2 property:hasName “John Smith” ;
property:hasAddress “47 Hope street” ;
property:hasPhone “333 222 111” .
Technology Primer SESAM4 Consortium 2009 – 2011
SESAM4 2011 Published under Creative Commons license

8. General RDF
 Basic data model is a “triple”
predicate
Subject Object
property:hasName
person:JS1 “John Smith”
property:hasFriend property:hasName
person:JS2 “John Smith”
Technology Primer SESAM4 Consortium 2009 – 2011
SESAM4 2011 Published under Creative Commons license

9. Why is RDF good?
 Globally unique identifier
 Extensible, distributed data model: just add triples
Name College Graduation Employer Salary
John Smith Stanford 1987 Apple Inc. US$160,000
... ... ... ... ...
 Guaranteed results!
 End of data silos!
 Integrate company data
 Expose selected company data
Technology Primer SESAM4 Consortium 2009 – 2011
SESAM4 2011 Published under Creative Commons license

10. Why RDF + OWL is even better
 Suppose you have a huge graph with tons of facts about
tons of people
 And you want to find potential customers
 “Well educated people working in a tech. company who is likely
to have disposable income, and willing to part with it”
 OWL allows you to build complex domain models and
define concepts like “potential customer”
 well educated = B.Sc. or Ph.D.
 tech company = company hasProduct (computer or mobile
phone or software)
 disposable income = hasSalary > 100,000 & (owns iPhone) or
(hasAccount FaceBook)
Technology Primer SESAM4 Consortium 2009 – 2011
SESAM4 2011 Published under Creative Commons license

11. Summary
 RDF is a simple, extensible, distributed data model
 Data integration
 Expose data
 Tools for “lifting” legacy data
 OWL
 Domain models: Ontologies
Simplifies finding the data you need
 RDF + OWL
 All the data, and just the data you want
Technology Primer SESAM4 Consortium 2009 – 2011
SESAM4 2011 Published under Creative Commons license

12. www.sesam4.net
Technology Primer SESAM4 Consortium 2009 – 2011
SESAM4 2011 Published under Creative Commons license