Very Gentle Linked Data Workshop

ELAG 2013 Workshop. Ghent, 29–30th May 2013

Adrian Stevenson and Jane StevensonMimas, University of Manchester, UK

@adrianstevenson @janestevenson

Very Gentle Linked Data

Workshop resources at http://bit.ly/verygentle 2

Workshop Resources

• All workshop resources available from:

http://bit.ly/verygentle

• Web address for resources in footer of each slide


Day 1

The goal of Linked Data is to enable people to share structured data on the Web as easily as they can share documents today.Bizer/Cyganiak/Heath Linked Data Tutorial, linkeddata.org


RDF Modelling – Pride and Prejudice

Linked Data Design Issues

• URIs• LD Design Issues• Triples

http://www.w3.org/DesignIssues/LinkedData.html

http://www.w3.org/DesignIssues/LinkedData.html

Triples• Triples statements– ‘Things’ have ‘properties’ with ‘values’– Subject – Predicate - Object

• Triples are the basis of RDF and Linked Data

ArchivalResource

Repository Provides Access To

Pride and Prejudice

Jane Austen Is Author Of

ArchivalResource

Finding Aid

EAD Document

Biographical History

Agent

Family Person Place

Concept

Genre Function

Organisation

maintainedBy/maintains

origination

associatedWith

accessProvidedBy/providesAccessTo

topic/page

hasPart/partOf

hasPart/partOf

encodedAs/encodes

Repository(Agent)

Book

Place

topic/page

Language

Level

administeredBy/administers

hasBiogHist/isBiogHistFor

foaf:focus Is-a associatedWith

level

Is-a

language

ConceptScheme

inScheme

ObjectrepresentedBy

PostcodeUnit

Extent

Creation

Birth Death

extent

participates in

TemporalEntity

TemporalEntity

at time

at time

product of

in

Archives Hub Model



URIs, Vocabs, Ontologies

• Need HTTP URIs for things to make links• Objects can be literal values – text, numbers• It’s important to state the type of resource– RDF Syntax provides rdf:type– Rdf:type used with classes e.g. bibo:Book,– dct:BibliographicResource

• Labels are very useful!– RDF Schema provides rdfs:label, rdfs:comment


Paper to machine - Serialisation

• Storing RDF in files is serialisation• Various forms for serialisation– N-triples, Turtle and RDF/XML– Notation 3 (N3) and RDFa

• Today we’ll be looking at n-triples and Turtle• RDF/XML quite complex and hard to read, but

tools available to convert between formats


Turtle

• Semicolon - another predicate and object coming for the same subject. The final object needs a dot (period) after it.

• Comma - the next triple has the same subject and predicate. The final object needs a dot (period) after it.


Hands on session writing n-triples and Turtle


Real Life Linked Data

• Transformation – Often using XSLT–MARC to RDF, MODS to RDF, EAD to RDF

• Matching Tools– SILK Framework• http://wifo5-03.informatik.uni-mannheim.de/bizer/silk/

http://wifo5-03.informatik.uni-mannheim.de/bizer/silk/




Day 2


Storing RDF - Triple Stores

• What? - a store for your triples!• Why? - efficiency – indexing• Useful for producing Linked Data views• Provides SPARQL endpoint that accepts queries

and returns results over HTTP (i.e. the Web!). • Results usually returned in ‘SPARQL Query

Results’ XML format• Many stores present results in user friendly form


Running Fuseki Triple Store

• Now we’ll aim to run a Fuseki triple store on your laptops

• If wifi working, all SPARQL examples should work with the British Library SPARQL endpoint:– http://bnb.data.bl.uk/sparql

• …BUT! You’ll need to LIMIT your queries

http://bnb.data.bl.uk/sparql

http://bnb.data.bl.uk/sparql


Querying RDF - SPARQL

• A SPARQL query comprises, in order:– Prefix declarations, for abbreviating URIs– A result clause, identifying what information to

return from the query– The query pattern, specifying what to query for in

the underlying dataset– Query modifiers, slicing, ordering, and otherwise

rearranging query results


SPARQL Query

• # prefix declarations PREFIX dct: <http://purl.org/terms/dc> ...

# result clause SELECT ...

# query pattern WHERE { ... }

# query modifiers ORDER BY ...


Hands on SPARQL Session


Linked Data Views

• Can use tools to provide Linked Data Views– Pubby• http://wifo5-03.informatik.uni-mannheim.de/pubby/

– ELDA• https://code.google.com/p/elda/

• Views important for making Linked Data de-referenceable and crawlable.




Building Applications on Linked Data

• We have explained today how to publish RDF and Linked Data

• The next step is to build applications using it• BBC is probably the best example• We’ve been working on Linking Lives project– http://archiveshub.ac.uk/linkinglives/

Martha Beatrice Webb

Place of birth: Gloucester, EnglandPlace of death: Liphook, Hampshire, England

Life dates: 1858-1943Epithet: social reformer and historianFamily name: Webb

Image

from: Beatrice Webb lettersBeatrice Webb (1858 - 1943). Fabian Socialist, social reformer, writer, historian, diarist. Wife, collaborator and assistant of Sidney Webb, later Lord Passfield. Together they contributed to the radical ideology first of the Liberal Party and later of the Labour Party. from: Beatrice Webb, A summer holiday in Scotland, 1884.Beatrice Webb (1858-1943), nee Potter, social reformer and diarist. Married to Sidney Webb, pioneers of social science. She was involved in many spheres of political and social activity including the Labour Party, Fabianism, social observation, investigations into poverty, development of socialism, the foundation of the National Health Service and post war welfare state, the London School of

Biographical Notes

Works

Our PartnershipMy ApprenticeshipThe case for the factory actsBeatrice Webb’s diaries; edited by Margaret ColeThe Diary

Knows

http://dbpedia.org/page/George_Bernard_Shaw

http://dbpedia.org/page/Sidney_Webb,_1st_Baron_Passfield

Workshop resources at http://bit.ly/verygentle

Contacts

26

Adrian Stevenson and Jane StevensonMimas, University of Manchester, [email protected]

[email protected]

www.twitter.com/adrianstevensonwww.twitter.com/janestevenson

mailto:[email protected]


CC License

This presentation available under creative commons Non Commercial-Share Alike:

http://creativecommons.org/licenses/by-nc/2.0/uk/

Education

Very Gentle Linked Data Workshop