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2011 05-02 linked data intro
- 1. Aristotle University, Departmentof Mathematics Master in Web Sciencesupported by Municipality of VeriaFrom Gore’s information highways to Obama’s Linked dataΜιχάλης Βαφόπουλος
- 2. From Al Gore(internet highways) to Barack Obama (linked data)2
- 3. The Web ofDocumentsAnalogy:a global file system
- 4. Designed for: humanconsumption
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- 6. Links between: documents(orsub-parts of)
- 7. Degree of structurein objects: fairly low
- 8. Semantics of contentand links: implicit (humans)(Tom Heath)The web = the internet+ links + documents3
- 9. The Web ofDocumentsSimple, big and unstructured
- 10. Organized in SilosButhumans are interested in:Things, no documents and
- 11. these Thingsmight beindocuments or elsewhereHumans: Limited capacity to extract meaning...4
- 12. Limited SEARCH capacitySearchfor: Football Players who went to the University of Texas at Austin, played for the Dallas Cowboys as Cornerback(Juan F. Sequeda)5
- 13. Google, Bing, yahoo!irrelevant6
- 14. Wikipedia through LD:relevant7
- 15. The Web ofDataAnalogy:a global filesystem----> globaldatabase
- 16. Designed for: humanconsumption ->machines first, humans later
- 17. Primary objects: documents--> things (or descriptions of things)
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- 19. Degree of structurein objects: fairly low ---> high
- 20. Semantics of contentand links: implicit --> explicit(Tom Heath)8
- 21. The Modigliani TestShowme all the locations of all the original paintings of ModiglianiDaniel Koller (@dakoller) showed that you can find this with a SPARQL query on DBpediaThanks Richard MacManus - ReadWriteWeb
- 23. Results of theModigliani TestAtanas Kiryakov from OntotextUsed LDSR – Linked Data Semantic RepositoryDbpediaFreebaseGeonamesUMBELWordnetPublished April 26, 2010: http://www.readwriteweb.com/archives/the_modigliani_test_for_linked_data.php
- 25. The Web ofData: why?– encourages reuse– reduces redundancy– maximises its (real and potential) inter-connectedness– enables network effects to add value to data13
- 26. The Web ofData: how?– current state on the WebRelational Databases
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- 30. XLS(see EXHIBIT)Computers can’tconsume data because:Different formats & models
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- 32. The Web ofData: how?– we need to create a standard way of publishing Data on the Web (like HTML for docs)This is the Resource Description Framework (RDF)(a simple example here from Juan F. Sequeda), more next semester!)15
- 33. Resource Description Framework(RDF)A data model
- 34. A way tomodel data
- 35. Inspired form Relationaldatabases and Logic
- 36. RDF is atriple data model
- 37. Labeled Graph (semanticnetworks)
- 38. Subject, Predicate, Object<Isidoro><was born in> <Chios><Chios> <is part of> <Greece>
- 39. The RDF DataModelTriplessubject -> predicate -> objectTom -> worksFor -> TalisTalis -> basedIn -> Birmingham<uri> -> <uri> -> <uri> or "literal"
- 40. παράδειγμα“Talis is BasedNear Birmingham”<http://dbpedia.org/resource/Talis_Group><http://xmlns.com/foaf/0.1/based_near><http://sws.geonames.org/3333125/>
- 42. Example: Document onthe Web
- 43. Databases back updocumentsTHINGS have PROPERTIES:A Book as a Title, an author, …This is a THING:A book title “Programming the Semantic Web” by Toby Segaran, …
- 44. Data representation inRDFProgramming the Semantic WebtitleauthorbookToby Segaranisbn978-0-596-15381-6publishernamePublisherO’Reilly
- 45. Everything on theweb is identified by a URI!
- 46. link the datato other dataProgramming the Semantic Webtitleauthorhttp://…/isbn978Toby Segaranisbn978-0-596-15381-6publishernamehttp://…/publisher1O’Reilly
- 47. consider the datafrom Revyu.comhasReviewhttp://…/review1http://…/isbn978descriptionreviewerAwesome Bookhttp://…/reviewernameJuan Sequeda
- 48. start to linkdatahasReviewhttp://…/review1http://…/isbn978Programming the Semantic WebtitledescriptionsameAshasReviewerAwesome Bookauthorhttp://…/isbn978Toby Segaranhttp://…/reviewernameisbn978-0-596-15381-6Juan Sequedapublishernamehttp://…/publisher1O’Reilly
- 49. Juan Sequeda publishesdata toohttp://juansequeda.com/idhttp://dbpedia.org/AustinlivesInnameJuan Sequeda
- 50. Let’s link moredatahasReviewhttp://…/review1http://…/isbn978descriptionhasReviewerAwesome Bookhttp://…/reviewernameJuan SequedasameAshttp://juansequeda.com/idhttp://dbpedia.org/AustinlivesInnameJuan Sequeda
- 51. And morehasReviewhttp://…/review1http://…/isbn978Programming theSemantic WebtitledescriptionsameAshasReviewerAwesome Bookauthorhttp://…/isbn978Toby Segaranhttp://…/reviewernameisbn978-0-596-15381-6Juan SequedapublishersameAshttp://…/publisher1nameO’Reillyhttp://juansequeda.com/idhttp://dbpedia.org/AustinlivesInnameJuan Sequeda
- 52. Linked data =internet + http + RDF
- 53. Linked Data PrinciplesUseURIs as names for thingsUse URIs so that people can look up (dereference) those names.When someone looks up a URI, provide useful information.Include links to other URIs so that they can discover more things.
- 54. Web as adatabaseLinked Data makes the web exploitable as ONE GIANT HUGE GLOBAL DATABASE!Is there any query language like sql?SPARQL… (next semester)
- 55. History of LDLinkedData Design Issues by TimBL July 2006
- 56. Linked Open DataProject WWW2007
- 57. First LOD CloudMay 2007
- 58. 1st Linked Dataon the Web Workshop WWW2008
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- 60. How to PublishLinked Data Tutorial ISWC2008
- 61. BBC publishes LinkedData 2008
- 62. 2nd Linked Dataon the Web Workshop WWW2009
- 63. NY Times announcementSemTech2009 - ISWC09
- 64. 1st Linked Data-a-thonISWC2009
- 65. 1st How toConsume Linked Data Tutorial ISWC2009
- 66. Data.gov.uk publishes LinkedData 2010
- 67. 2st How toConsume Linked Data Tutorial WWW2010
- 68. 1st International Workshopon Consuming Linked Data COLD2010
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- 71. What is aLinked Data application/service?Software system that makes use of data on the Web from multiple datasets and that benefits from links between the datasets
- 72. Characteristics of LinkedData ApplicationsConsume data that is published on the web following the Linked Data principles: an application should be able to request, retrieve and process the accessed data
- 73. Discover further informationby following the links between different data sources: the fourth principle enables this.
- 74. Combine the consumedlinked data with data from sources (not necessarily Linked Data)
- 75. Expose the combineddata back to the web following the Linked Data principles
- 76. Offer value toend-usersthe 5 stars of open linked data★make your stuff available on the Web (whatever format)★★make it available as structured data (e.g. excel instead of image scan of a table)★★★non-proprietary format (e.g. csv instead of excel)★★★★use URLs to identify things, so that people can point at your stuff★★★★★link your data to other people’s data to provide contexthttp://lab.linkeddata.deri.ie/2010/star-scheme-by-example/
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- 80. Greece – notin Linked Data!
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