Embedding libraries
and cultural memory institutionsin the Linked Data cloudThomas Baker
Dublin Core Metadata Initiative
International Symposium on Knowledge Communities 2012
Research Center for Knowledge Communities
University of Tsukuba
15 December 2012

Data Web – the Cloud…

Linking Open Data
cloud diagramby Richard Cyganiak and Anja Jentzsch
http://lod-cloud.net/

2Description of a scientific article...

Topic of the article
Is “acrididae”, i.e.
“grasshoppers”.
One author is named“Lu Hui”.

3Triplifying the description…
Subject

PredicateObjectagris:CN2009002389

has the Title

典型草原三种蝗虫种群死
亡率的研究agris:CN2009002389

has an Author

Lu Hui

agris:CN2009002389

has a Topic

Acrididae (grasshoppers)

A URI identifying the article
Resource A is identified by the URI http://agris.fao.org/resource/CN2009002389.
Let’s abbreviate this as agris:CN2009002389.
4

Triplifying the description…
Subject

PredicateObjectagris:CN2009002389

has the Title

典型草原三种蝗虫种群死
亡率的研究

agris:CN2009002389

has an Author

agris-author:luhui

agris-author:luhui

has the Name

Lu Hui

agris:CN2009002389

has a Topic

Acrididae (grasshoppers)

A URI identifying the author
The author is identified by the URI http://agris.fao.org/author/luhui.
Let’s abbreviate this as agris-author:luhui.
5Triplifying the description…
Subject

PredicateObjectagris:CN2009002389

has the Title

典型草原三种蝗虫种群死
亡率的研究

agris:CN2009002389

has an Author

agris-author:luhui

agris-author:luhui

has the Name

Lu Hui

agris:CN2009002389

has a Topic

agrovoc:c_4416

agrovoc:c_4416

has preferred label

Acrididae (en)agrovoc:c_4416

has preferred label

蝗科 (zh)A URI identifying the subjectThe description of http://aims.fao.org/aos/agrovoc/c_4416 in the AGROVOC
Concept Scheme tells us how this concept is labeled in English and in Chinese.
6

Triplifying the description…
Subject

PredicateObjectagris:CN2009002389

dct:title

典型草原三种蝗虫种群死
亡率的研究

agris:CN2009002389

dct:creator

agris-author:luhui

agris-author:luhui

foaf:name

Lu Hui

agris:CN2009002389

dct:subject

agrovoc:c_4416

agrovoc:c_4416

has preferred label

Acrididae (en)agrovoc:c_4416

has preferred label

蝗科 (zh)URIs identifying properties(from Dublin Core and SKOS)
7

Triplifying the description…
SubjectPredicate

Objectagris:CN2009002389

dct:title

典型草原三种蝗虫种群死
亡率的研究

agris:CN2009002389

dct:creator

agris-author:luhui

agris-author:luhui

foaf:name

Lu Hui

agris:CN2009002389

dct:subject

agrovoc:c_4416

agrovoc:c_4416

skos:prefLabel

Acrididae (en)agrovoc:c_4416

skos:prefLabel蝗科 (zh)URIs identifying properties(from SKOS)
8

Triples seen as a graphagris:CN…389

dct:title
dct:subject

agrovoc:c_4416

dct:creator
agris-author:
luhui

典型草…

foaf:name

Lu HuiSubject

PredicateObjectagris:CN2009002389

dct:title

典型草原三种蝗虫种群死
亡率的研究

agris:CN2009002389

dct:creator

agris-author:luhui

agris-author:luhui

foaf:name

Lu Hui

agris:CN2009002389

dct:subject

agrovoc:c_4416

9

Computers detect URIs that match...
agris:CH…179

dct:title

Heuschrecken

dct:subject

dct:creator
agris-author:
peterbagrovoc:c_4416

foaf:namePeter, B.

dct:subject
agris:CN…389

dct:title

dct:creator
agris-author:luhuiagrovoc:c_4416

典型草…
foaf:name

Lu Hui10

…thus “linking” the descriptions
agris:CH…179

dct:title

Heuschrecken

dct:subject

dct:creator
agris-author:
peterbAn infinitely
expandable
description

agrovoc:c_4416

foaf:namePeter, B.

dct:subject
agris:CN…389

dct:title

dct:creator
agris-author:
luhui

典型草…
foaf:name

Lu Hui11

Expanding to other Web resources
VIVO Expert

AGRIS record

AGROVOC
concept

DBPedia
concept

BBC News

BBC Web page

Wikipedia
page

12

“Records” have become clusters of links
SKOS

AGRIS record
AGROVOCFOAFAGRIS Authors

Dublin Core13

Traditional IT maps between Records
Schema A

Schema B
sameasSchema CmappedtoLinked Data applications create good triples
Application A

Application B

Application C

Linked Data “speaks for itself”...
Application A

Application B

Application C

…as long as source datasetsand vocabularies are preserved
SKOS

Dataset
FOAFDC

Dataset

VIAFLCSH

What Linked Data uses URIs forConcept

PersonObjectCorporate Body

EventPlace...and the relationships
between them (properties)
18

FRBR theory“WEMI”

Concept

PersonWork

ObjectCorporate Body

Expression

Event

Manifestation

Place

Item

19

FRBR theory“WEMI”

can stand alone
must relate to only one
Work?
must relate to one
or more Expressions?

Do entities inherit from must relate to only
higher levels?
one Manifestation?
2011-09-19

UDC-2011, The Hague

20Replacing cataloging rules?
• Resource Description and Access (RDA)– Successor to AACR for library catalogs– Tied to FRBR ontology– Better support for relationships– Implies Work and Expression for every
bibliographic item
– Like FRBR, relatively untested

21Replacing MARC format?
• Bibframe Initiative– Library of Congress replacement for MARC
– http://www.loc.gov/marc/transition/pdf/marcld-report-11-21-2012.pdf• Has Work, but model is simpler than WEMI
• First draft, November 2012:– More about data structures than “ontology”?
– Like Application Profiles...?

22

LOD resource description• Application Profiles (Dublin Core-style)– Use any syntax mappable to Linked Data
– Use any combination of RDF vocabularies– Define “record”-like data packages– From very simple descriptions, to complex,depending on requirements...

23

LOD e-commerce description• Schema.org– Structured information about People, Hotels,
Recipes, Books, Movies…
– Uses RDFa to embed descriptions in Web pages– Indexed by Google, Yahoo…
– Oriented more to high-impact e-commerce than
to the “long tail” of scientific and cultural data

2011-09-19

UDC-2011, The Hague

24

LOD concept description• W3C Web Ontology Language (OWL) models“reality” to support inference– If Dog is a sub-class Mammal, and “Oscar” is aDog, then “Oscar” is a Mammal• Define a “cartoon universe” (Dogs, Cats,Mammals)• Can be difficult and expensive to design

25LOD concept description• SKOS Concept Schemes– W3C Simple Knowledge Organization System– SKOS pragmatically avoids supporting inference– If Car is broader than Wheel, and Machine isbroader than Car, Machine is not “broader than”
Wheel• OWL and SKOS provide URIs for Linked Data– SKOS is easier, often “good enough”
2011-09-19

UDC-2011, The Hague

26

Making RDF publication easier

Drupal 7 content management
Easy workflows help non-experts publish on Web
 Uses RDFa embedded in Web pages (likeschema.org)
 Can output other RDF serialization formats(RDF/XML, Turtle, JSONLD…)
 Support for SPARQL endpoints
Simplicity scales better• Many can agree on small standards (SKOS, DC,RDF)• A few can agree on large complex standards(FRBR, RDA)
• Rare for many to agree on large complexstandards

28

Recipe for Interoperability
1. What elements of your data really need tointeroperate?
2. Map those parts to a core model.
3. Define the core model using URIs and RDF.
4. Publish the core data elements as Linked
Data.

29

Learning Linked Data
• RDF is a language for data
– DC, SKOS, LCSH... – the “words” of its dictionaries– RDF Triples based on a “sentence grammar”• Fluency in RDF– Language designed for humans for processing bymachines– Software tools to read, analyze, compose data...
– “RDF as a second language”
30

tom@tombaker.org