An introduction to Linked Data and to the Linked Open Copac and Archives Hub project.

1. How to Become a First Class Citizen of the Web Linked Data and the LOCAH project Jane Stevenson & Adrian Stevenson

2. Remit This session will give a brief overview of the concepts behind Linked Data and will explain how we are applying these ideas to archival and bibliographic data. Archives Hub: merged catalogue of archival descriptions from 200 institutions across the UK Copac: merged catalogue of bibliographic records from libraries across the UK

3. Introduction

4. The goal of Linked Data is to enable people to share structured data on the Web as easily as they can share documents today. [The creation of] a space where people and organizations can post and consume data about anything. Bizer/Cyganiak/Heath Linked Data Tuturial, linkeddata.org

5. 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

6. Linked Data encourages open data, open licences and reuse. …but Linked Data does not have to be open.

7. Core questions Is it achievable? Will it bring substantial benefits? “It is the unexpected re-use of information which is the value added by the web”

8. What is Linked Data? 4 ‘rules’ of for the web of data: Use URIs as names for things Use HTTP URIs so that people can look up those names. When someone looks up a URI, provide useful information, using the standards (RDF, SPARQL) Include links to other URIs. so that they can discover more things. http://www.w3.org/DesignIssues/LinkedData.html

9. Giving Things identifiers We can make statements about things and establish relationships by assigning identifiers to them. Jane Stevenson = http://archiveshub.ac.uk/janefoaf.rdf Manchester = http://dbpedia.org/resource/manchester English = http://lexvo.org/id/iso639-3/eng

10. URIs Uniform Resource Identifiers (URIs) are identifiers for entities (people, places, subjects, records, institutions). They identify resources, and ideally allow you to access representations of those resources. Think not of locations, but of identifiers! For Linked Data you use HTTP URIs Jane Stevenson = http://archiveshub.ac.uk/janefoaf.rdf Manchester = http://dbpedia.org/resource/manchester English = http://lexvo.org/id/iso639-3/eng

11. Entities and Relationships

12. Triple statement AccessProvidedBy Archival Resource Repository ProvidesAccessTo Subject: Archival Resource Predicate: AccessProvidedBy Object: Repository Subject > Predicate > Object

13. HTTP URIs ArchivalResource: http://data.archiveshub.ac.uk/id/findingaid/gb-106-7esp <accessProvidedBy> Repository: http://data.archiveshub.ac.uk/id/repository/gb106 Archival Resource Repository accessProvidedBy

14. An RDF Graph Title has Archival Resource Repository heldAt describedBy encodedAs Finding Aid EAD document

15. So...? 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 BBC Copac VIAF DBPedia GeoNames Archives Hub

16. The Linking benefits of Linked Data BBC:Cranford Copac:Cranford VIAF:Dickens DBPedia: Gaskell Hub:Gaskell Geonames:Manchester DBPedia: Dickens Hub:Dickens

17. The Web of ‘Documents’ Global information space (for humans) Document paradigm Hyperlinks Search engines index and infering relevance Implicit relationships between documents Lack of semantics

18. The Web of Linked Data Global data space (for humans and machines) Making connections between entities across domains (people, books, films, music, genes, medicines, health, statistics...) LD is not about searching for specific documents or visiting particular websites, it is about things - identifying and connecting them. Closely aligned to the general architecture of the Web

19. From one thing…to the same thing <sameAs> http://dbpedia.org/resource/manchester http://sws.geonames.org/2643123 http://data.archiveshub.ac.uk/id/concept/ncarules/manchester Are they the same?

20. Vocabularies & Ontologies

21. Vocabularies & Ontologies Vocabulary: set of terms Ontology: organisation of terms – hierarchy, relationships

22. Shared vocabularies Problems of data integration: information exchange across independently designed systems Two different databases: one for films one for actors To collaborate using their current databases, the owners of either site would have to decide on a common data format by which to share information that they could both understand by using a common film and actor unique ID scheme of their own invention.

23. Need ‘film title’; ‘actor name’; ‘actor birthdate’, etc. to mean the same thing to each Use the same vocabulary Query both databases. No need for transformations, mappings, contracts

24. Vocabularies in Linked Data Common vocabulary to describe the data, e.g. ‘film-title’ means the same thing Adopt the same ontologies for expressing meaning Use semantics to link data Want to avoid transformation, mapping, contracts between data providers

25. Shared use of vocabularies DC DC Copac Hub Hub RDF Copac RDF foaf bibo foaf skos skos dcterms:title dcterms:identifier

26. Ontologies Many widely used ontologies Use others as far as possible Use your own where necessary Dublin Core Friend of a Friend (FOAF) Simple Knowledge Organisation System (SKOS) Bibo Open Cyc

27. Linked Data on the Hub & Copac Linked Open Copac and Archives Hub: Locah JISC funded project August 2010 – July 2011 Mimas UKOLN Eduserv

28. What is LOCAH doing? Part 1: Exposing the Linked Data Part 2: Creating a prototype visualisation Part 3: Reporting on opportunities and barriers

29. How are we exposing the Data? Model our ‘things’ into RDF Transform the existing data into RDF/XML Enhance the data Load the RDF/XML into a triple store Create Linked Data Views Document the process, opportunities and barriers on LOCAH Blog

30. 1. Modelling ‘things’ into RDF Hub data in ‘Encoded Archival Description’ EAD XML form Copac data in ‘Metadata Object Description Schema’ MODS XML form Take a step back from the data format Think about your ‘things’ What is EAD document “saying” about “things in the world”? What questions do we want to answer about those “things”? http://www.loc.gov/ead/ http://www.loc.gov/standards/mods/

31. 1. Modelling ‘things’ into RDF Need to decide on patterns for URIs we generate Following guidance from W3C ‘Cool URIs for the Semantic Web’ and UK Cabinet Office ‘Designing URI Sets for the UK Public Sector’ http://data.archiveshub.ac.uk/id/findingaid/gb1086skinner ‘thing’ URI … is HTTP 303 ‘See Other’ redirected to … http://data.archiveshub.ac.uk/doc/findingaid/gb1086skinner document URI … which is then content negotiated to … http://data.archiveshub.ac.uk/doc/findingaid/gb1086skinner.htmlhttp://data.archiveshub.ac.uk/doc/findingaid/gb1086skinner.rdf http://data.archiveshub.ac.uk/doc/findingaid/gb1086skinner.turtlehttp://data.archiveshub.ac.uk/doc/findingaid/gb1086skinner.json http://www.w3.org/TR/cooluris/http://www.cabinetoffice.gov.uk/resource-library/designing-uri-sets-uk-public-sector

32. 1. Modelling ‘things’ into RDF Using existing RDF vocabularies: DC, SKOS, FOAF, BIBO, WGS84 Geo, Lexvo, ORE, LODE, Event and Time Ontologies Define additional RDF terms where required, hub:ArchivalResource copac:BibiographicResource hub:maintenanceAgency copac:Creator It can be hard to know where to look for vocabs and ontologies Decide on licence – CC BY-NC 2.0, CC0, ODC PDD

33. Archives Hub Model (as at 14/2/2011) in Finding Aid Place PostcodeUnit Repository(Agent) administeredBy/administers maintainedBy/maintains encodedAs/encodes hasPart/partOf EAD Document accessProvidedBy/providesAccessTo Level Biographical History topic/page hasBiogHist/isBiogHistFor Language level ArchivalResource language at time topic/page origination hasPart/partOf TemporalEntity Creation product of associatedWith extent inScheme Extent Concept ConceptScheme Agent representedBy Object foaf:focus Is-a Is-a associatedWith Family Person Organisation Place Book participates in Genre Function Birth Death TemporalEntity at time

34. Copac Model (as at November 2010)

35. Feedback Requested! We would like feedback on the model Appreciate this will be easier when the data available Via blog http://blogs.ukoln.ac.uk/locah/2010/09/28/model-a-first-cut/ http://blogs.ukoln.ac.uk/locah/2010/11/08/some-more-things-some-extensions-to-the-hub-model/ http://blogs.ukoln.ac.uk/locah/2010/10/07/modelling-copac-data/ Via email, twitter, in person

36. 2. Transforming in RDF/XML Transform EAD and MODS to RDF/XML based on our models Hub: created XSLT Stylesheet and used Saxon parser http://saxon.sourceforge.net/ Saxon runs the XSLT against a set of EAD files and creates a set of RDF/XML files Copac: created in-house Java transformation program

37. 3. Enhancing our data Language - lexvo.org Time periods - reference.data.gov.uk Geolocation - UK Postcodes URIs and Ordnance Survey URIs Names - Virtual International Authority File Matches and links widely-used authority files - http://viaf.org/ Names (and subjects) - DBPedia Subjects - Library of Congress Subject Headings

38. 4. Load RDF/XML into triple store Using the Talis Platform triple store RDF/XML is HTTP POSTed We’re using Pynappl Python client for the Talis Platform http://code.google.com/p/pynappl/ Store provides us with a SPARQL query interface

39. 5. Create Linked Data Views Expose ‘bounded’ descriptions from the triple store over the Web Make available as documents in both human-readable HTML and RDF formats (also JSON, Turtle, CSV) Using Paget ‘Linked Data Publishing Framework’ http://code.google.com/p/paget/ PHP scripts query Sparql endpoint

40. http://data.archiveshub.ac.uk/id/archivalresource/gb1086skinner

41. http://data.archiveshub.ac.uk/

42. Can I access the Locah Linked Data? Will be releasing the Hub data very soon! Copac data will follow approx 1 month later Release will include Linked Data views, Sparql endpoint details, example queries and supporting documentation

43. Reporting on opportunities and barriers Locah Blog (tags: ‘opportunities’ ‘barriers’) Feed into #JiscEXPO programme evidence gathering More at: http://blogs.ukoln.ac.uk/locah/2010/09/22/creating-linked-data-more-reflections-from-the-coal-face/ http://blogs.ukoln.ac.uk/locah/2010/12/01/assessing-linked-data

44. Creating the Visualisation Prototype Based on researcher use cases Data queried from Sparql endpoint Use tools such as Simile, Many Eyes, Google Charts For first Hub visualisation using Timemap – Googlemaps and Simile http://code.google.com/p/timemap/

45. 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

46. Sir Ernest Henry Shackleton http://archiveshub.ac.uk/data/gb15sirernesthenryshackleton Archives related to Shackleton: VIAF URL: http://viaf.org/viaf/12338195/ Books related to Shackleton: Biographical History: Ernest Henry Shackleton was born on 15 February 1874 in Kilkea, Ireland, one of six children of Anglo-Irish parents. The family moved from their farm to Dublin, where his father, Henry studied medicine. On qualifying in 1884, Henry took up a practice in south London, and between 1887 and 1890, Ernest was educated at Dulwich College. On leaving school, he entered the merchant service, serving in the square-rigged ship Hoghton Tower until 1894 when he transferred to tramp steamers. In 1896, he qualified as first mate, and two years later, was certified as master, joining the Union Castle line in 1899. [more]

47. The challenges

48. The learning process Model the data, not the description The description is one of the entities Understand the importance of URIs Think about your world before others …but external links are important Try to get to grips with terminology

49. Names 6947115KNAPPF F Knapp associated with record 6947115 /id/agent/6947115KNAPPF <copac:isCreatorOf rdf:resource="http://data.copac.ac.uk/id/mods/6947115"/> 6957115KNAPPF 6947115 <isCreatorOf>

50. Index terms (names, subjects, places) ‘AssociatedWith’ as the relationship Benefits of structured index terms Use /person/ and /organisation/ in the URI Distinguish /person/pilkington’ the person and /organisation/pilkington Distinguish place/reading/ and subject/reading/

51. Problems with source data EAD very permissive: whole range of finding aids Copac more consistent but still wide variety Hub EAD: We limited the tags we worked with Large files (around 5Mb) tend to need splitting up

52. Duplication of data “So statements which relate things in the two documents must be repeated in each. This clearly is against the first rule of data storage: don't store the same data in two different places: you will have problems keeping it consistent.” (T B-L www.w3.org/designissues/linkeddata.html)

53. Archival Inheritance “Do not repeat information at a lower level of description that has already been given at a higher level.” ISAD(G) Many elements do not apply to ‘child’ descriptions Simple rule of inheritance not always appropriate LD does assert hierarchical relationships but no requirement to follow these links

54. Copac Larger community: more potential vocabularies/documentation/support/confusion/inconsistencies Merged catalogues: a unique scenario ‘Creator’ and ‘Others’ (editor, authors, illustrator) Learning from Hub / Doing what is appropriate Usually not right or wrong answers

55. Copac model Groundwork done with Archives Hub. Then had to decide what we wanted to say about the data Challenges over what a ‘record’ is – ‘Bleak House’ from each contributor? or one merged record? In many ways simpler than archival data; but also can decide to create a simpler model

56. Copac Model

57. Copac specification Hard to start but proved to be very crucial Very iterative process between spec and RDF output Important to establish the structure of the spec (we used tabs for each ‘entity’)

58. Copac specification

59. Copac decisions Where to create Copac URIs – copac:creator copac:contributor copac:heldBy When to create URIs Title = literal Publication place = URI How to deal with problematic/ambiguous data Date? = productionDate

60. Issues

61. Risks Can you rely on data sources long-term? Persistence of persistent URIs? New technologies Investment of time – unsure of benefits Licensing issues

62. Provenance Track which data comes from our sources: URIs identify your entities Linked Data tends towards disassembling Copac/Hub as trusted sources…is DBPedia (for example) as reliable? Contributors may want data to be identified Issues around administrative/biographical history Benefits of trust? Users may want to know where data is from

63. Licensing Nature of Linked Data: each triple as a piece of data ‘Ownership’ of data? Data often already freely available (M2M interfaces)

64. Licensing Public Domain Licences: simple, explicit, and permit widest possible reuse. Waive all rights to the data BL, British National Bibiography uses public domain licence Limit commercial uses? Build in community norms: attribution, share alike - to reinforce desire for acknowledgement Legal situation?

65. Thank You

66. Attribution and CC licence Sections of this presentation adapted from materials created by other members of the LOCAH Project This presentation available under creative commonsNon Commercial-Share Alike:http://creativecommons.org/licenses/by-nc/2.0/uk/