The document discusses the concepts and implementation of linked data and the semantic web. It describes Cambridge University Library's COMET project which converted bibliographic records from MARC21 format to RDF triples and published them as linked open data with HTTP URIs. The project aimed to release data for open use and gain experience working with semantic web technologies like RDF, SPARQL and triplestores. Key challenges included dealing with IPR issues in MARC21 records and developing tools to transform and link the data.

1. Ed Chamberlain Systems Development Librarian Cambridge University Library

2. Disclaimers … Apologies if you see the semantic web as up there with quantum mechanics … Will contain some techy stuff Not that much on Voyager …

3. Overview Linked data in theory What we learnt IPR Data Supporting technology How could it be used by Ex Libris?

4. What is the semantic web? “ The Semantic Web is a "man-made woven web of data" that facilitates machines to understand the semantics , or meaning, of information on the World Wide Web [1] [2 ] .” “ The concept of Semantic Web applies methods beyond linear presentation of information ( Web 1.0 ) and multi-linear presentation of information ( Web 2.0 ) to make use of hyper-structures leading to entities of hypertext.” http://en.wikipedia.org/wiki/Semantic_Web

5. Eh? Semantic = its meaning is explained - self-describing data! Hyperlinked = meaning contextualised elsewhere Focus on machines rather than people

6. What is Linked Data … After several iterations of semantic web development … Tim Berners-Lee has advocated four underlying design principles for linked 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

7. And RDF ? The Resource Description Framework ( RDF ) is a family of World Wide Web Consortium (W3C) specifications originally designed as a metadata data model . It has come to be used as a general method for conceptual description or modeling of information that is implemented in web resources, using a variety of syntax formats. http://en.wikipedia.org/wiki/Resource_Description_Framework

8. What does this mean in practice … RDF Data is expressed as triples: DC XML … <dc:identifer>1000346</dc:identifer> <dc:title>Early medieval history of Kashmir : [with special reference to the Loharas] A.D. 1003-1171</dc:title> Marc21 … 001 1000346 245$aEarly medieval history of Kashmir : $b[with special reference to the Loharas] A.D. 1003-1171 / RDF triples … <http://data.lib.cam.ac.uk/id/entry/cambrdgedb_1000346> <http://purl.org/dc/terms/title> &quot;Early medieval history of Kashmir : [with special reference to the Loharas] A.D. 1003-1171&quot; .

9. Most of a record … 1. <http://data.lib.cam.ac.uk/id/entry/cambrdgedb_1000346> <http://purl.org/dc/terms/title> &quot;Early medieval history of Kashmir : [with special reference to the Loharas] A.D. 1003-1171&quot; . 2. <http://data.lib.cam.ac.uk/id/entry/cambrdgedb_1000346> <http://purl.org/dc/terms/type> <http://data.lib.cam.ac.uk/id/type/1cb251ec0d568de6a929b520c4aed8d1> . 3. <http://data.lib.cam.ac.uk/id/entry/cambrdgedb_1000346> <http://purl.org/dc/terms/type> <http://data.lib.cam.ac.uk/id/type/46657eb180382684090fda2b5670335d> . 4. <http://data.lib.cam.ac.uk/id/entry/cambrdgedb_1000346> <http://purl.org/dc/terms/identifier> &quot;UkCU1000346&quot; . 5. <http://data.lib.cam.ac.uk/id/entry/cambrdgedb_1000346> <http://purl.org/dc/terms/issued> &quot;1981&quot; . 6. <http://data.lib.cam.ac.uk/id/entry/cambrdgedb_1000346> <http://purl.org/dc/terms/creator> <http://data.lib.cam.ac.uk/id/entity/cambrdgedb_a5a6f7a184ff02e08b1befedc1b3a4d0> . 7. <http://data.lib.cam.ac.uk/id/entry/cambrdgedb_1000346> <http://purl.org/dc/terms/language> <http://id.loc.gov/vocabulary/iso639-2/eng> . 8. <http://data.lib.cam.ac.uk/id/entry/cambrdgedb_1000346> <http://RDVocab.info/ElementsplaceOfPublication> <http://id.loc.gov/vocabulary/countries/ii>

10. Where is the linking exactly? <http://data.lib.cam.ac.uk/id/entry/cambrdgedb_1000346> <http://purl.org/dc/terms/creator> <http://data.lib.cam.ac.uk/id/entity/cambrdgedb_a5a6f7a184ff02e08b1befedc1b3a4d0 > <http://data.lib.cam.ac.uk/id/entity/cambrdgedb_a5a6f7a184ff02e08b1befedc1b3a4d0> <http://www.w3.org/2000/01/rdf-schema#label> &quot;Mohan, Krishna&quot; . <http://data.lib.cam.ac.uk/id/entity/cambrdgedb_a5a6f7a184ff02e08b1befedc1b3a4d0> <http://www.w3.org/1999/02/22-rdf-syntax-ns#type> <http://xmlns.com/foaf/0.1/Person> . <http://data.lib.cam.ac.uk/id/entity/cambrdgedb_a5a6f7a184ff02e08b1befedc1b3a4d0> <http://xmlns.com/foaf/0.1#name> &quot;Mohan, Krishna&quot; .

11. External linking <http://data.lib.cam.ac.uk/id/entry/cambrdgedb_1000346> <http://purl.org/dc/terms/subject> <http://data.lib.cam.ac.uk/id/entry/cambrdgedb_43e3fa1b4404410454c90d8022578852> . <http://data.lib.cam.ac.uk/id/entry/cambrdgedb_43e3fa1b4404410454c90d8022578852> <http://www.w3.org/1999/02/22-rdf-syntax-ns#type> <http://www.w3.org/2004/02/skos/core#Concept> . <http://data.lib.cam.ac.uk/id/entry/cambrdgedb_43e3fa1b4404410454c90d8022578852> <http://www.w3.org/2004/02/skos/core#inScheme> <http://id.loc.gov/authorities#conceptScheme> . <http://data.lib.cam.ac.uk/id/entry/cambrdgedb_43e3fa1b4404410454c90d8022578852> <http://www.w3.org/2004/02/skos/core#prefLabel> &quot;Lohars -- History&quot; . <http://data.lib.cam.ac.uk/id/entry/cambrdgedb_43e3fa1b4404410454c90d8022578852> <http://purl.org/dc/terms/hasPart> <http://id.loc.gov/authorities/sh85078149#concept> .

12. Live demo … http://data.lib.cam.ac.uk/id/entry/cambrdgedb_1000346

13. Meanwhile … BNB British Museum Library of Congress BBC Nature

14. The Linking Open Data cloud diagram - http : //richard . cyganiak .de/2007/10/lod /

15. What was COMET? Cambridge Open Metadata Cambridge University Library / CARET / OCLC Funded by the JISC Infrastructure for Resource Discovery Project February to July 2011 http://discovery.ac.uk

16. What did COMET do … Experimentally convert as much of the Cambridge University Library catalogue as it could from Marc21 to RDF triples Investigate IPR issues around Open License publishing and Marc21 Construct an RDF publishing platform to site behind those URI’s … Release tools for others to do the same Blog and documentation

17. Why? Respond to academic / national demand for Open Data Get our data to non-librarians! Tax-payer value-for-money CUL already provides public APIs Gain in-house experience of RDF Move library services forward

18. Why - IPR Linked data works best with a permissive license CC0 or Public Domain Data License Non-commercial licenses not suitable Conflict with record vendors

19. How – IPR Examine contracts with major vendors Decide on re-use conditions and contact them Decode record ownership from Marc21 fields (Could not use Voyager SQL)

20. How – IPR Where does a record come from ? Several places in Marc21 where this data could be held (015,035,038,994 …) Logic and hierarchy for examination Attempt at scripted analysis – list bib_ids by record vendor

22. What - IPR Most vendors happy with permissive license for ‘non-marc21’ formats RLUK / BL B.N.B. – PDDL OCLC – ODC-By Attribution license No good reason not to re-publish – need the right license!

23. IPR - What did we learn? Marc21 not fit for purpose here, no ‘authoritative code’ for license National / international mandate to release open data No good reason not to re-publish – need the right license!

24. How - data Several attempts – settled on SQL extracts based on lists of bib_ids Use Perl scripting to ‘munge’ the data You can try this at home ! (work)

25. How - marc problems Punctuation as a function Binary encoding Numbers for field names Bad characters Replication of data in fields

26. How – data vocab RDF allows you to freely mix vocabularies Emerging consensus on bibliographic description Our conversion script is CSV customisable BL and others leading the way

27. How - data publishing Bulk downloads Queryable ‘endpoints’ Data and code at http://data.lib.cam.ac.uk

28. How – linking PHP script to match text against LOC subject headings – enrich with LOC GUID FAST / VIAF enrichment courtesy of OCLC

29. Data - What did we learn ? Marc / AACR2 cannot translate will to semantically rich formats Need better container / transfer standards (not necessarily RDF)

30. What else?

31. RDF friendly database Called RDF stores, triplestores or Quadstores Vary in size scale and scope None are particularly admin / dev friendly right now …

32. How - SPARQL Query language for RDF stores Still a work in progress Some similarities with SQL Bibliographic-centric tutorial

33. How –storage and access ARC2 - Lightweight MYSQL / PHP solution Good fit for a six month project Great for around 3-500 k records Not so good for 1 million plus 20 million + ?

34. Supporting tech -What did we learn? Triplestores are cumbersome SPARQL alone does not do the trick High entry barrier to RDF is partly a result of these accompanying technologies

35. What does this mean for Ex Libris Building whole systems around RDF is not really a good idea Need the flexibility to do this by dropping Marc21 GUIDS for records (or allow us to have our own) – resolvable ? Ensure any RDF publishing capacity is flexible (as ours is) RDF capability for Primo ?

36. Always add value to RDF … Standalone RDF is just fiddly Dublin Core, so … Create httpd URI’s for entities Link it to something useful (LOC, FAST, VIAF) Endpoint (SPARQL?) Don’t limit to the bibliographic

37. Beyond bibliographic Bibliographic Holdings FAST subject headings Libraries Transactions Special collections Archives Creator / entity Place of publication LCSH subject headings Course lists Language Librarians

38. Do what Tim said … 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

39. Questions? @edchamberlain / [email_address] http://data.lib.cam.ac.uk http://cul-comet.blogspot.com/