This document discusses linked data life cycles, including modeling, publishing, discovery, integration, and use cases. It describes key concepts like dataspaces, DSSPs, linked data principles, and the linked open data cloud. Challenges with linked data include schema mapping, write-enablement, authentication, and dataset dynamics as data sources change over time.

1. Linked Datalife cycles Dr. Michael Hausenblas, Linked Data Research CentreDERI, NUI Galway July 2011

2. What is a dataspace? Heterogeneous data sources Distributed environment - proximity Find and consume data Update data

3. What is a DSSP and why does it matter? DSSP == Dataspace Support Platform Participants & relationships Services Catalog & Browse Search & Query Index Discovery Linked Data ecosystem is an open & standards-basedreal-world DSSP

4. Data management solutions Based on [Franklin:SIGMOD05]

5. Linked Data principles* Use URIs to identify the “things” in your data Use HTTP URIs so people and machines can look them up (on the Web) When a URI is looked up, return a description of the thing Include links to related things * http://www.w3.org/DesignIssues/LinkedData.html

6. http://lod-cloud.net/ Linked Open Data cloud

7. Linked Open Data cloud stats triples distribution links distribution http://lod-cloud.net/state/

9. The Web: distributed & open  lacks control

11. Linked Data life cycles: data awareness opendata.ie LOD cloud Neologism DataCube prefix.cc Google Refine RDB2RDF VoID DCAT Sindice CKAN LATC 24/7 duke Sig.ma school explorer data-gov.ie

12. http://thinkquarterly.co.uk/01-data/a-data-state-of-mind/ Hans Rosling ‘database hugging disorder’

13. TimBL’s 5-star plan for open data* ★ Make your data available on the Web under an open license ★★ Make it available as structured data(Excel sheet instead of image scan of a table) ★★★Use a non-proprietary format(CSV file instead of an Excel sheet) ★★★★ Use Linked Data format(URIs to identify things, RDF to represent data) ★★★★★ Link your data to other people’s data to provide context *http://lab.linkeddata.deri.ie/2010/star-scheme-by-example/

15. Linked Data life cycles: modeling opendata.ie LOD cloud Neologism DataCube prefix.cc Google Refine RDB2RDF VoID DCAT Sindice CKAN LATC 24/7 duke Sig.ma school explorer data-gov.ie

16. http://linked-statistics.org/datacube/

17. http://vocab.deri.ie http://neologism.deri.ie

18. http://schema.rdfs.org

19. Linked Data life cycles: publishing opendata.ie LOD cloud Neologism DataCube prefix.cc Google Refine RDB2RDF VoID DCAT Sindice CKAN LATC 24/7 duke Sig.ma school explorer data-gov.ie

20. Publishing http://lab.linkeddata.deri.ie/2010/grefine-rdf-extension/

21. Linked Data life cycles: discovery opendata.ie LOD cloud Neologism DataCube prefix.cc Google Refine RDB2RDF VoID DCAT Sindice CKAN LATC 24/7 duke Sig.ma school explorer data-gov.ie

22. Discovery Model for dataset description: VoID vocabulary Users in industry and governments Published as W3C Notehttp://www.w3.org/TR/void Significant uptake in research

23. Describing Datasets General dataset metadata Access metadata Structural metadata Describing linksets Deployment and discovery of voiD files

24. Linked Data life cycles: integration opendata.ie LOD cloud Neologism DataCube prefix.cc Google Refine RDB2RDF VoID DCAT Sindice CKAN LATC 24/7 duke Sig.ma school explorer data-gov.ie

25. Why going for the 5th star? Central Contractor Registration (CCR) Geonames http://webofdata.wordpress.com/2011/05/22/why-we-link/

26. Pay-as-you-go integration Fix Overall Data IntegrationEffort http://latc-project.eu/

27. Linked Data life cycles: use cases opendata.ie LOD cloud Neologism DataCube prefix.cc Google Refine RDB2RDF VoID DCAT Sindice CKAN LATC 24/7 duke Sig.ma school explorer data-gov.ie

29. School explorer

30. Linked Data life cycles opendata.ie LOD cloud Neologism DataCube prefix.cc Google Refine RDB2RDF VoID DCAT Sindice CKAN LATC 24/7 duke Sig.ma school explorer data-gov.ie

31. Challenges Schema mapping, matching, alignment[Hausenblas:DBKDA10] Write-enable the LD world [Berners-Lee:DERITR09] Authentication and authorisation in a distributed setuphttp://www.w3.org/2005/Incubator/webid/ REST-alignment of Linked Data[Wilde:WEWST09] Dataset dynamics[Umbrich:LDOW10]

32. References [Franklin:SIGMOD05] M. J. Franklin, A. Y. Halevy, and D. Maier, From databases to dataspaces: a new abstraction for information management.SIGMOD Record, 34(4):27–33, 2005. [Berners-Lee:DERITR09] T. Berners-Lee, R. Cyganiak, M. Hausenblas, J. Presbrey, O. Seneviratne, and O. Ureche. On Integration Issues of Site-Specific APIs into the Web of Data. DERI Technical Report, 2009. [Hausenblas:DBKDA10] M.Hausenblas and Marcel Karnstedt.Understanding Linked Open Data as a Web-Scale Database. Second International Conference on Advances in Databases, Knowledge, and Data Applications, 2010. [Wilde:WEWST09] E. Wilde and M. Hausenblas.RESTful SPARQL? You Name It! Aligning SPARQL with REST and Resource Orientation. Fourth Workshop on Emerging Web Services Technology Workshop at European Conference on Web Services, Eindhoven, The Netherlands, 2009. [Umbrich:LDOW10] J. Umbrich, M. Hausenblas, A. Hogan, A. Polleres, and S. Decker.Towards Dataset Dynamics: Change Frequency of Linked Open Data Sources. Third International Workshop on Linked Data on the Web at 19th International World Wide Web Conference, Raleigh, North Carolina, USA, 2010.

34. Linked Data core specificationshttp://linkeddata-specs.info

35. Enabling cross-boundary access to data sourceshttp://enable-cors.org

36. Linked Open Data 5-star deployment schemehttp://lab.linkeddata.deri.ie/2010/star-scheme-by-example/