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LOCAH Project and Considerations of Linked Data Approaches
29th March 2011
JISC Managing Research Data International Workshop, Birmingham, UK
Adrian Stevenson
LOCAH Project Manager
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“The term Linked Data refers to a set of best practices for publishing and connecting structured data on the Web.”
“the Semantic Web is the goal or end result… Linked Data provides the means to reach that goal”
From ‘Linked Data: The Story So Far’ - Heath, Bizer and Berners-Lee 2009
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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
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In essence, it marks a shift in thinking from publishing data in human readable HTML documents to machine readable documents. That means that machines can do a little more of the thinking work for us.
http://www.linkeddatatools.com/semantic-web-basics
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• But haven’t we been putting linked data on the web for years?– In CSV , relational databases, XML etc?
• Well yes, but these approaches are not so easy to integrate
• Web 2.0 mashups work against a fixed set of data sources
• Linked Data applications operate on top of an unbound, global data space.
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So what’s been happening?
BBC Music
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A little bit of the techy stuff
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Linked Data is …
• A way of publishing data on the web that:– Encourages reuse– Reduces redundancy– Maximises inter-connectedness– Enables network effects
• So how is this achieved?
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Presentational tagging – HTML
• <h1>Manchester Physiotherapy Centre</h1> <p>Welcome to the Manchester Physiotherapy Centre home page. Do you feel pain? Have you had an injury? Let our staff take care of your body and soul.</p>
<h2>Consultation hours</h2> Mon 11am - 7pm<br/> Tue 11am - 7pm<br/> Wed 3pm - 7pm<br/> Thu 11am - 7pm<br/> Fri 11am - 3pm
• <p> Please note that we will not be offering consultation during the weeks of the <a href=". . .">Olympic</a> games.</p>
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Semantic tagging<company>
<treatmentOffered>Physiotherapy</treatmentOffered>
<companyName>Manchester Physiotherapy Centre</companyName>
<staff>
<therapist>Lisa Davenport</therapist><therapist>Steve Matthews</therapist>
<secretary>Kelly Townsend</secretary>
</staff>
</company>
Linked Data Design Issues
• URIs
• LD Design Issues
• Triples
http://www.w3.org/DesignIssues/LinkedData.html
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URIs and HTTP
• A ‘Uniform Resource Identifier’ (URI) provides a simple and extensible means for identifying a resource - RFC 3986
• HTTP URIs can be ‘de-referenced’• A URL is a type of URI
• HTTP URIs are used for “real world” things• http://adrianstevenson.com/id/me• http://dbpedia.org/page/Tim_Berners-Lee
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RDF• Resource Description Framework
– a language for representing information about resources on the Web
– RDF can be used to represent things identified on the Web, even when they cannot be directly retrieved on the Web
• Describes relations using ‘triples’
• http://www.w3.org/TR/REC-rdf-syntax/
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Triples• Triples statements
– ‘Things’ have ‘properties’ with ‘values’– Subject – Predicate - Object
• Triples are the basis of RDF
ArchivalResource
Repository Provides Access To
The Rolling Stones
Keith Richards Is Member Of
BBC Music
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LOCAH Project
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What is the LOCAH Project?
• Linked Open Copac and Archives Hub• Funded by #JiscEXPO 2/10 ‘Expose’
call• 1 year project. Started August 2010
• http://blogs.ukoln.ac.uk/locah/ tag: #locah
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What are the Archives Hub and Copac?• National data services• The Archives Hub is an aggregation of
archival descriptions from archive repositories across the UK– http://archiveshub.ac.uk
• Copac provides access to the merged library catalogues of libraries throughout the UK, including all national libraries– http://copac.ac.uk
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What is LOCAH Doing?
• Part 1: Exposing Archives Hub & Copac data as Linked Data
• Part 2: Creating a prototype visualisation
• Part 3: Reporting on opportunities and barriers
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LOCAH Linked Data
• If something is identified, it can be linked to• We can then take items from one dataset
and link them to items from other datasets
BBCBBCVIAFVIAF
DBPediaDBPediaArchives
HubArchives
Hub
CopacCopac
GeoNamesGeoNames
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BBC:CranfordBBC:Cranford
VIAF:DickensVIAF:Dickens
DBpedia: Gaskell
DBpedia: Gaskell
Hub:GaskellHub:Gaskell
Copac:CranfordCopac:Cranford
Geonames:ManchesterGeonames:Manchester
DBpedia: Dickens
DBpedia: Dickens Hub:DickensHub:Dickens
The Linking benefits of Linked Data
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 (as at 14/2/2011)
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Enhancing our data• Already have some links:
– lexvo.org URIs for languages of archival materials– reference.data.gov.uk URIs for time periods– Postcodes, using both UK Postcodes URIs and
Ordnance Survey URIs – Virtual International Authority File
• Matches and links widely-used authority files - http://viaf.org/
– DBPedia
• Also looking at:– Library Congress Subject Headings
http://data.archiveshub.ac.uk/id/archivalresource/gb1086skinner
http://data.archiveshub.ac.uk/doc/person/ncarules/chamberlainarthurneville1869-1940statesman
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How are we creating the Visualisation Prototype?
• Based on researcher use cases
• Data queried from Sparql endpoint
• Use tools such as Simile, Many Eyes, Google Charts
• Also looking at custom built prototype
Use Case Slide
http://www.w3.org/2005/Incubator/lld/wiki/Use_Case_LOCAH
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Visualisation Prototype• Using Timemap –
– Googlemaps and Simile
– http://code.google.com/p/timemap/
• Early stages with this• Will give location and
‘extent’ of archive.• Will link through to
Archives Hub
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Some issues
• Data Modelling
• Sustainability
• Provenance
• Licensing
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Data Modelling Challenges• Archival description is hierarchical and
multi-level
• Archives Hub: inconsistencies in data and lack of standardisation– there's no content standard in the UK
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Sustainability
• Can you rely on data sources long-term?
• Ed Summers at the Library of Congress createdhttp://lcsh.info
• Linked Data interface for LOC subject headings
• People started using it
Library of Congress Subject Headings
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Provenance
• Triples create individual statements
• OK if data ‘watermarked’
• But can often be a problem
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Licensing
• Nature of Linked Data: each triple as a piece of data
• ‘Ownership’ of data
• Hard to track attribution
• We’re using CC BY-NC 2.0 for now
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Questions?
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Attribution and CC License
• Sections of this presentation adapted from materials created by other members of the LOCAH Project
• This presentation available under creative commons Non Commercial-Share Alike:
http://creativecommons.org/licenses/by-nc/2.0/uk/
