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Publishing and Using Linked Open Data

Richard J. Urban, Ph.D.

School of Library and Information StudiesFlorida State Universityrurban@fsu.edu@musebrarian

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January 10, 2013Thursday’s Schedule

• 9-10:30 am Class Session: Publishing Linked Data & Linked Data Applications

• 10:30-10:45 am break

• 10:45-Noon Class Session: Linked Open Data

• Noon- 1:00 pm Lunch

• 1:00-3:00 pm Class Session: Open Project Studio

• 3:00-3:15 pm Break

• 3:15-5:00 pm Class Session: Open Project Studio

• 5:30-7:30 pm DHWI Banquet

Humanities Plain and Simple

Location: Colony Ballroom 2203, Stamp Student Union

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PUBLISHING LINKED DATA & LINKED DATA APPLICATIONS

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http://linkeddatabook.com/editions/1.0/#htoc61

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Connect to Existing Data

• SIMILE RDFizershttp://simile.mit.edu/wiki/RDFizers

• D2RQ non-RDF relational data to RDFhttp://d2rq.org/

• OAI2LOD https://github.com/behas/oai2lod

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Publish Files

• What’s the right syntax for your audience?• How to version instance and ontology

data?• Thinking about URIs

– URIs that follow your classes– Not based on underlying software– Designed to persist– URIs for resources vs. URIs for data

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Triplestores: Questions to ask

• What methods can be used to store data?– In Memory, SQL,mySQL, Postgres, etc.

• What level of expressivity is supported?– RDFs, OWL Lite, OWL DL, etc.– Reasoner support

• What rule languages are supported?– SWRL, etc.

• Support for contexts/named graphs• What does the API support?

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Triplestores

• Jenahttp://jena.apache.org/

• Sesamehttp://www.openrdf.org/

• W3C Triplestore resourcehttp://www.w3.org/2001/sw/wiki/Category:Triple_Store

• Virtuoso (proprietary) http://virtuoso.openlinksw.com/

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Interfaces

• Drupal 7http://drupal.org/project/rdf– See also RDF specific modules

• Pubbyhttp://wifo5-03.informatik.uni-mannheim.de/pubby/

• Semantic Wikihttp://semantic-mediawiki.org/wiki/Semantic_MediaWiki

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Embedding Linked Data

• RDFa– http://www.w3.org/TR/xhtml-rdfa-primer/

• Schema.org• Schema.org + RDF

http://schema.rdfs.org/

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LINKED OPEN DATA

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Linked Open Data Criteria

★ Available on the web (whatever format), but with an open license

★★ Available as machine-readable structured data (e.g. excel instead of image scan of a table)

★★★ as (2) plus non-proprietary format (e.g. CSV instead of excel)

★★★★ All the above plus, Use open standards from W3C (RDF and SPARQL) to identify things, so that people can point at your stuff

★★★★★ All the above, plus: Link your data to other people’s data to provide context

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IP

• Risk Management• What’s your risk tolerance?

– Tolerance of your institution?

• Not saying anything about your data IP isn’t much better than a restrictive license.

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Licensing Data

• Open Data Commonshttp://opendatacommons.org/

• Creative Commons 0http://creativecommons.org/choose/zero/

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Humanities Data Citation Practices

• Where do we stand?• How to best give attribution when we use

triples from another source?– Published documentation– Provenance metadata

• What does this attach too?

• DCMI Provenance Metadatahttp://dublincore.org/groups/provenance/

• W3C Provenance WGhttp://www.w3.org/2011/prov/wiki/Main_Page

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For the long run

• DH Data Curation Handbook - Policy, Practice, and Lawhttp://guide.dhcuration.org/legal/policy/

• How will data be maintained over the long term.

• Clear licenses can facilitate preservation.

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Economics of Linked Data

• How to adapt Linked Data to closed publication models?– Make identifiers publically available.– Provide some limited information when the

URI is used. – Release taxonomies/vocabularies as separate

data.