Linked Data A Personal Perspective

1. Linked DataA Personal Perspective Janifer Gatenby OCLC EMEA With acknowledgements to Richard Wallis and Anila Angjeli

2. What is it? • What does it promise? • How do we get there? • What happens when we get there?

3. What is it? • Not really a new way of linking but a new way of expressing a link It is about using canonical trusted globally referenceableidentifiers for concepts, people, organisations, locations etc. instead of copying text strings and losing the connection with the authoritative sources they came from. Richard Wallis

4. MARC21 links • 700 10 $a name $e role $0 authority control number • (added entry in a MARC record for a name related to a work, not the main author) These familiar links reference an authority record in the same database as a bibliographic record, hence have no address portion. Linked data extends the linking range.

5. Extending the linking range: URI • URI – immutable address as well as an identifier • http://id.loc.gov/authorities/names/nr89009099 • http://viaf.org/viaf /116774723 • http://isni-url.oclc.nl/isni/000000114556841 9 NACO libraries – LC, National Agricultural Library, National Library of Medicine, British Library, NL Mexico, NLNZ, NL Scotland, NL South Africa, NL Wales

6. Extending the linking range: RDF • RDF – metadata is expressed in triples • Data • Data label (properties) • Vocabulary from which the label comes (gives context to the label)

7. Linked Data Principles • Use URIs as names for things • Use HTTP URIs so people can look up those names • When someone looks up a URI, provide useful information, using the standards - RDF • Include links to other URIs, so that they can discover more Tim Berners-Lee - 2006

8. Vocabularies • Vocabularies are not schemas, they are lists of defined data labels (concepts) • Schema.org (Search engines) • BibFrame (Library community) • FOAF Friend of a friend • OWL same as • Vocabularies can be mixed foaf:name "Jimmy Wales" ; foaf:mbox <mailto:jwales@bomis.com> ; foaf:homepage <http://www.jimmywales.com/> ; foaf:nick "Jimbo" ;

9. What does it promise? • Enriched displays without data maintenance • Better harvesting and ranking • because of markup • and because of links • Navigation to pages with additional information – • Example: from VIAF via ISNI to encyclopaedias, rights management societies (digitisation rights), Bowker – biographies from fly leaves

12. Interconnecting French cultural heritage treasures on the Web OtherBnF resources Digital documents (DC) External resources Web pages for Internet users BnF Archives and Manuscripts catalogue (EAD) heterogeneous resources Raw data for machines Modeling Matching Clustering Alignments Semantic Web techniques BnF Main catalogue (MARC)

13. example (soon) ISNI 0000 0001 2283 1567 BnF persistent ID Links ImportedfromWikipedia and integrated in the page

14. vocabularies used Existingones + othersdefined for the specificneeds of the project Data canbedownloaded Information about the data model (or ontology) at : http://data.bnf.fr/about-en

15. How do we get there? DNB CultureGraph • “It’s all about creating connections” • DDC to RVK (German classification) by comparing search results • GND (names) to German Wikipedia

16. Example VIAF • Ingesting data to compare and create links • Makes clusters; cluster identifier • Ingesting preferred to external linking • Wikipedia, ISNI, WorldCat identities • More data used for clustering, so more reliable • VIAFBot for making reciprocal links in Wikipedia / Wikidata <rdf:typerdf:resource="http://xmlns.com/foaf/0.1/Person"/> <rdf:typedf:resource="http://rdvocab.info/uri/schema/FRBRentitiesRDA/Person"/> <foaf:name>De Groot, Gerard J., 1955-</foaf:name> <foaf:name>DeGroot, Gerard J., 1955-</foaf:name> <rdaGr2:dateOfBirth>1955-06-22</rdaGr2:dateOfBirth> <owl:sameAsrdf:resource="http://data.bnf.fr/ark:/12148/cb12299846b#foaf:Person"/> <owl:sameAs rdf:resource="http://www.idref.fr/034977651/id"/> <owl:sameAs rdf:resource="http://d-nb.info/gnd/12422900X"/>

17. Music Rights Text Rights Trade Sources Encyclopaedias Libraries Researchers & Professional

18. 7 million NEW LINKS to & from VIAF ì Linked Data: isni-url.oclc.nl/isni/

19. ISNI – an identifier • Identifiers Seal Uniqueness: “n” number of other elements are necessary for uniqueness • Stable identifier; stable metadata: • assigned where there is confidence in the quality and completeness of the metadata to establish uniqueness • ISNI system + Quality Team (BL & BnF) Linking erroneous data propagates errors.

20. Links are made once and inherited, e.g. by local catalogues • URI – immutable address as well as an identifier • http://id.loc.gov/authorities/names/nr89009099 • http://viaf.org/viaf /116774723 • http://isni-url.oclc.nl/isni/000000114556841 9 NACO libraries – Library of Congress, National Agricultural Library, National Library of Medicine, British Library, NL Mexico, NLNZ, NL Scotland, NL South Africa, NL Wales

21. What happens when we get there? • Search happens mostly in the search engines • Library catalogue concentrates on: • Being linked to (& linking out) • Delivery, particularly of the digitised and immediate

22. What happens when we get there? • How do search and linked data interact? • Is search really fully delegated to search engines & larger union catalogues?

23. Types of search The more your catalogue is linked in, the more likely it is to attract all types of searches

24. Links plus data needed in catalogues It is about using canonical trusted globally referenceableidentifiers for concepts, people, organisations, locations etc. instead of copying text strings and losing the connection with the authoritative sources they came from. • Data needed • For making indexes • For comparisons, e.g. For de-duplication • Data mining This doesn’t mean that you only need the links; you often also need to ingest the data • Besides data storage no longer the restraint it once was

25. Richard Wallis: Further Reading • http://www.slideshare.net/tulipbiru64/the-single-power-of-link-richard-wallis • http://www.slideshare.net/rjw/linked-data-and-oclc