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Linking Open Data | ODP
Linked Open Data:  Principles & 2 Projects Prof. Dr. Stefan Gradmann Humboldt-Universität zu Berlin / School of Library and Information Science [email_address]
Overview Linked Data:  What is it, how does it work?
LoD & LOD2:  two projects
Conclusion : on the importance of being 'open'
From the Web of Documents to the Linked Data Web The Document Web:  Information Management: A Proposal  (TBL, 1989). Built on Documents  („Information   Resources“)
Untyped HTTP  links The Web of Linked Open  Data can be understood as an extension of the document web In  syntax  (RDF)
In  scope  (including re-   presentations of non-   information resources,    'things', 'data')
Syntactically Extending the  Document Web (1) We add a syntax for making statements on resources: RDF Or, more generally triples ... … where S and P are web resources (identified using URIs) and O is either a web resource or a literal
Syntactically Extending the  Document Web (2) We add a schema language (RDFS) with elements such as classes,
hierarchies of classes and properties,
inheritance
support for basic inferencing. And thus are able to establish structures in triple aggregations resulting in lightweight domain ontologies:
Extending the Web in Scope: the way it does  not  work! Taken from Ronald Carpentier's Blog at  http://carpentier.wordpress.com/ 2007/08/08/1-2-3/ Something  is  wrong with this picture (but what?)
…  and the way extending the Web in scope is actually done: A Web of Things
… Linked Data Copyright ©  2008 W3C (MIT, ERCIM, Keio) http://www.w3.org/2008/Talks/0617-lod-tbl/#(4) Standard  Identifiers Standard  Pointers Standards for  Queries   and  Statements Link  to Context
A few Bubbles: 5/2007 < Over 500 million RDF triples  < Around 120,000 RDF links between data sources © Richard Cyganiak
Quite some Bubbles: 9/2008 © Richard Cyganiak
Many Bubbles: 7/2009 © Richard Cyganiak < Over 13.1 billion RDF triples  < Over 142 million RDF links between data sources
(Too?) Many Bubbles: 9/2010 http://richard.cyganiak.de/2007/10/lod/lod-datasets_2010-09-22_colored.html

Linking Open Data

  • 1.
    Linked Open Data: Principles & 2 Projects Prof. Dr. Stefan Gradmann Humboldt-Universität zu Berlin / School of Library and Information Science [email_address]
  • 2.
    Overview Linked Data: What is it, how does it work?
  • 3.
    LoD & LOD2: two projects
  • 4.
    Conclusion : onthe importance of being 'open'
  • 5.
    From the Webof Documents to the Linked Data Web The Document Web: Information Management: A Proposal (TBL, 1989). Built on Documents („Information Resources“)
  • 6.
    Untyped HTTP links The Web of Linked Open Data can be understood as an extension of the document web In syntax (RDF)
  • 7.
    In scope (including re- presentations of non- information resources, 'things', 'data')
  • 8.
    Syntactically Extending the Document Web (1) We add a syntax for making statements on resources: RDF Or, more generally triples ... … where S and P are web resources (identified using URIs) and O is either a web resource or a literal
  • 9.
    Syntactically Extending the Document Web (2) We add a schema language (RDFS) with elements such as classes,
  • 10.
    hierarchies of classesand properties,
  • 11.
  • 12.
    support for basicinferencing. And thus are able to establish structures in triple aggregations resulting in lightweight domain ontologies:
  • 13.
    Extending the Webin Scope: the way it does not work! Taken from Ronald Carpentier's Blog at http://carpentier.wordpress.com/ 2007/08/08/1-2-3/ Something is wrong with this picture (but what?)
  • 14.
    … andthe way extending the Web in scope is actually done: A Web of Things
  • 15.
    … Linked DataCopyright © 2008 W3C (MIT, ERCIM, Keio) http://www.w3.org/2008/Talks/0617-lod-tbl/#(4) Standard Identifiers Standard Pointers Standards for Queries and Statements Link to Context
  • 16.
    A few Bubbles:5/2007 < Over 500 million RDF triples < Around 120,000 RDF links between data sources © Richard Cyganiak
  • 17.
    Quite some Bubbles:9/2008 © Richard Cyganiak
  • 18.
    Many Bubbles: 7/2009© Richard Cyganiak < Over 13.1 billion RDF triples < Over 142 million RDF links between data sources
  • 19.
    (Too?) Many Bubbles:9/2010 http://richard.cyganiak.de/2007/10/lod/lod-datasets_2010-09-22_colored.html
  • 20.
    EDM and LinkedOpen Data Europeana Information Space Context Data DBpedia
  • 21.
    PND and SWD(prototype)
  • 22.
  • 23.
  • 24.
  • 25.
    Linking Open DataInitiative of the Semantic Web Education and Outreach (SWEO) interest group of W3C http://www.w3.org/wiki/SweoIG/TaskForces/CommunityProjects/LinkingOpenData
  • 26.
    “ The goal[...] is to build a data commons by making various open data sources available on the Web as RDF and by setting RDF links between data items from different data sources.”
  • 27.
    First gathering inBanff at WWW2007 with pioneers such as Tom Heath , Chris Bizer , Kingsley Idehen, Yrjana Rankka, Orri Erling, Ivan Mikhailov, Danny Ayers, Steve Coast, Peter Murray Rust, Alan Ruttemberg, Ian Horrocks, Bernardo Cuenca Grau, Boris Motik, Danny Gagne.
  • 28.
    Current discussion: howto switch from mere volume to quality ? Matching, mapping and referrals are central
  • 29.
    Tom Heath andChristian Bizer (2011) Linked Data: Evolving the Web into a Global Data Space (1st edition). Morgan & Claypool. http://linkeddatabook.com/editions/1.0/
  • 30.
    LOD2 Large-scale integratingproject co-funded by the European Commission within the FP7 framework (09/2010 – 08/2014, Total Budget: 8,58 M€, Total Funding: 6,45 M€, Total Resources: 844 PM) -> http://lod2.eu/Welcome.html
  • 31.
    Builds on theLinked Open Data cloud and extends it with a technology stack for enabling application building . The stack includes: Comprehensive Knowledge Archive Network (CKAN, registry)
  • 32.
  • 33.
  • 34.
    OntoWiki (agile, distributedknowledge engineering)
  • 35.
  • 36.
    Openlink Virtuoso (data,information, and knowledge management) Consortium: Universität Leipzig (Sören Auer, lead), Centrum Wiskunde & Informatica, Digital Enterprise Research Institut (DERI), Freie Universität Berlin, OpenLink Software, Semantic Web Company, TenForce, Exalead, Wolters Kluwer, Open Knowledge Foundation
  • 37.
    … andthe political bit
  • 38.
    On the Importanceof being 'Open' (1) “ Openness (allowing access) is separate question.” (TBL, http://www.w3.org/2008/Talks/0617-lod-tbl/#(22))
  • 39.
    Does Linked Datawork without being 'open' ? Technically speaking: yes (cf. pharma industry or biomedical data)
  • 40.
    But it getsquite expensive that way …
  • 41.
    … muchtoo expensive, probably, for Europeana to afford!
  • 42.
    Or else (LD behind a proxy) it is straightaway parasitic.
  • 43.
    And much ofits 'semantic' charms of open flow of RDF statements and reasoning potential would be lost in such a setting, anyway. As a consequence, we aim at Europeana data being Open Linked Data (more in a Europeana Foundation statement at http://bit.ly/fe637P ) and at Europeana data being under CC0!
  • 44.
    On the Importanceof being 'Open' (2) This has a number of implications No control over data usage
  • 45.
    No income tobe generated from data access and use
  • 46.
    Innovative and (commercially)attractive services can be built on LoD -> Do not repeat mistakes we are very familiar with from the Open Access debates of the past 10 years! 'open' = 'free',
  • 47.
    'free' vs. 'commercial'-> Do not exclude commercial reuse for Europeana metadata!
  • 48.
    -> Whatis the actual value of context (in business terms!)?
  • 49.
    Thank you for your attention!

Editor's Notes

  • #14 Europeana intends to connect to the Linked Open Data community. In the Linked Open Data cloud we find many more knowledge sources like Dbpedia, Geonames, or Library of Congress Subject Headings. Europeana wants to use them to further contextualize and enrich the objects in its information space. At the same time Europeana wants to make its own data available to other communities. The EDM is crucial for realizing this vision. [ LOD cloud July 2009 ]