SKOS & Linked DataAlexander O’Connor

<Alex.OConnor@scss.tcd.ie>

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Tuesday 6 March 12

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Tuesday 6 March 12

Linked Open Data

1.On the Web, Open License

2.Machine Readable

3.Non-proprietary Format

4.RDF Standards

5. Linked RDF

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Tuesday 6 March 12

Linked Open Data

1.On the Web, Open License

2.Machine Readable

3.Non-proprietary Format

4.RDF Standards

5. Linked RDF

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Tuesday 6 March 12

How to Link Data?•Links happen at the instance level

•cf. Hyperlinks in HTML

•OWL:SameAs -- equivalence

•RDF:SeeAlso -- associative

Bib:aBook OWL:SameAs DBPedia:aBook.

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owl:sameAs• http://www4.wiwiss.fu-berlin.de/eurostat/resource/regions/Berlin• fbase:Berlin• http://linkedgeodata.org/triplify/node/240109189#id• http://sws.geonames.org/2950159/

DBPedia Berlin

• Can use one concept list to query another databse:• ask Geonames about the concept known in DBPedia as Berlin

http://dbpedia.org/page/Berlin

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Agenda•RDF Recap•Vocabularies, Thesauri, KOSes•SKOS•SKOS-Mapping•Other Key Linked Data Vocabularies

•Dublin Core•Organisations•FOAF

•Linking Data•Asssignment

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Tuesday 6 March 12

How do we Establish

a Common Understanding?3

Tuesday 6 March 12

How do we Establish

a Common Understanding?

Agreed set of words (Vocabulary)

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Tuesday 6 March 12

How do we Establish

a Common Understanding?

Agreed set of words (Vocabulary)

Agreed set of word groups (Thesaurus)

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Tuesday 6 March 12

How do we Establish

a Common Understanding?

Agreed set of words (Vocabulary)

Agreed set of word groups (Thesaurus)

Agreed word Hierarchy (Taxonomy)

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Tuesday 6 March 12

How do we Establish

a Common Understanding?

Agreed set of words (Vocabulary)

Agreed set of word groups (Thesaurus)

Agreed word Hierarchy (Taxonomy)

Agreed Concepts & Relationships (Ontology)

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Tuesday 6 March 12

How do we Establish

a Common Understanding?4

Tuesday 6 March 12

How do we Establish

a Common Understanding?

Agreed File Format

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Tuesday 6 March 12

How do we Establish

a Common Understanding?

Agreed File Format

Agreed Character Set

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Tuesday 6 March 12

How do we Establish

a Common Understanding?

Agreed File Format

Agreed Character Set

Agreed Transfer Protocol

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Tuesday 6 March 12

How do we Establish

a Common Understanding?

Agreed File Format

Agreed Character Set

Agreed Transfer Protocol

Agreed Representation

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Tuesday 6 March 12

RDF Recap

http://www.sxc.hu/photo/3328725

Tuesday 6 March 12

aBook

RDF Graph

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“Javascript”^^xsd:String

aBookhasTitle

RDF Graph

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Tuesday 6 March 12

“Javascript”^^xsd:String

aBookhasTitle

0596000480^^xsd:integerhasIsbn

RDF Graph

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Tuesday 6 March 12

“Javascript”^^xsd:String

aBookhasTitle

0596000480^^xsd:integerhasIsbn

aPublisherhasPublisher

“O’Reilly”^^xsd:StringhasName

RDF Graph

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Tuesday 6 March 12

“Javascript”^^xsd:String

aBookhasTitle

0596000480^^xsd:integerhasIsbn

aPublisherhasPublisher

“O’Reilly”^^xsd:StringhasName

aBook aPublisher

is-ais-a

RDF Graph

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Tuesday 6 March 12

Turtle

@PREFIX Ex:<http://example.com/>

exampleOne a Ex:Example.

exampleOne hasColour “Red”@en.

exampleOne hasOther Ex:ExampleTwo.

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Tuesday 6 March 12

Exercise 1: Write Triples

“Javascript”^^xsd:String

aBookhasTitle

0596000480^^xsd:integerhasIsbn

aPublisherhasPublisher

“O’Reilly”^^xsd:StringhasName

aBook aPublisher

is-ais-a

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Tuesday 6 March 12

SPARQLPREFIX Bib: <http://ex.org/Bib/>

SELECT ?isbn, ?title

WHERE {

?Book a Bib:Book.

?Book Bib:isbn ?isbn.

?title Bib:title "Javascript" .

}

?Book

?isbn

“Javascript”hasTitle

hasIsbn

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Tuesday 6 March 12

SKOS

http://www.sxc.hu/photo/85963414

Tuesday 6 March 12

SimpleKnowledgeOrganisationSystem

(for the web)16

Tuesday 6 March 12

SimpleKnowledgeOrganisationSystem

(for the web)

Simple, machine readable format for

KOS

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Tuesday 6 March 12

SimpleKnowledgeOrganisationSystem

(for the web)

Simple, machine readable format for

KOS

Small Core with extensions

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Tuesday 6 March 12

SimpleKnowledgeOrganisationSystem

(for the web)

Simple, machine readable format for

KOS

Small Core with extensions

Support Decentralised,

Information Sharing

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Tuesday 6 March 12

Some SKOS Applications

2.1 Use Case #1 — An integrated view to medieval illuminated manuscripts

• 2.2 Use Case #2 — Bio-zen ontology framework for representing scientific discourse in life science

• 2.3 Use Case #3 — Semantic search service across mapped multilingual thesauri in the agriculture domain

• 2.4 Use Case #4 — Supporting product life cycle• 2.5 Use Case #5 — CHOICE@CATCH ranking of candidate terms for

description of radio and TV programs• 2.6 Use Case #6 — BIRNLex: a lexicon for neurosciences• 2.7 Use Case #7 — Radlex: a lexicon for radiology• 2.8 Use Case #8 — NSDL Metadata Registry

http://www.w3.org/TR/2009/NOTE-skos-ucr-2009081817

Tuesday 6 March 12

Some SKOS Applications

2.1 Use Case #1 — An integrated view to medieval illuminated manuscripts

• 2.2 Use Case #2 — Bio-zen ontology framework for representing scientific discourse in life science

• 2.3 Use Case #3 — Semantic search service across mapped multilingual thesauri in the agriculture domain

• 2.4 Use Case #4 — Supporting product life cycle• 2.5 Use Case #5 — CHOICE@CATCH ranking of candidate terms for

description of radio and TV programs• 2.6 Use Case #6 — BIRNLex: a lexicon for neurosciences• 2.7 Use Case #7 — Radlex: a lexicon for radiology• 2.8 Use Case #8 — NSDL Metadata Registry

http://www.w3.org/TR/2009/NOTE-skos-ucr-2009081818

Tuesday 6 March 12

Exercise 2

•Examine the Library of Congress Subject Headings

•What classes/properties would you suggest?

http://www.loc.gov/aba/cataloging/classification/lcco/lcco_q.pdf

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Terms & Concepts

http://www.slideshare.net/seanb/skos-past-present-and-future20

Tuesday 6 March 12

Relationship Model

http://www.slideshare.net/seanb/skos-past-present-and-future22

Tuesday 6 March 12

Labels

http://www.slideshare.net/seanb/skos-past-present-and-future

•Lexical Labels associated with Concepts•Preferred: one per language•Alternate: variants •Hidden: mis-spellings

•No domains stated, so usage possible on any resource.

•Labels pairwise disjoint.

•Label Extension (SKOS-XL) provides additional support for descriptions of labels and links

between them•E.g. acronyms, abbreviations

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Documentation

http://www.slideshare.net/seanb/skos-past-present-and-future24

Tuesday 6 March 12

Semantic Relations

http://www.slideshare.net/seanb/skos-past-present-and-future

•Hierarchical and Associative (Taxonomy & Thesaurus)•Broader/Narrower

•Loose (i.e. no formal) semantics•A publishing vehicle, not a set of

thesaurus construction guidelines•Domain/Range restrictions on semantic relations•Broader/narrower not transitive in SKOS

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Exercise

Devise a Taxonomy for Digital Humanities

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Library of Congress

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Tuesday 6 March 12

Library of Congress

http://id.loc.gov/authorities/subjects/sh2002000569.html#concept

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SKOS Mapping• Used to state mapping (alignment) links between SKOS concepts in

different concept schemes

• Hierarchichal

• skos:broadMatch

• skos:narrowMatch

• Associative

• skos:relatedMatch

• Equivalence

• skos:closeMatch

• skos:exactMatch

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equivalent in some sensenot transitive

strongly equivalentis transitive

Tuesday 6 March 12

Summary•Organise Knowledge to suit

•Distributed

•Decentralised

•SKOS for terms, builds on RDF

•Reuse common Vocabularies for everything else

•Interlink Instances

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Links

•http://dublincore.org/resources/training/NISO_Webinar_20120222/NISO-DCMI_Webinar_20120222.pdf

•http://www.sameas.org

•http://wordnet.princeton.edu

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