Datamodel and API

1. Data Model and API
Nuno Freire
RLUK Hack Day
London, 14th
of May 2014

2. Outline
 The data model
• The entities, properties and URIs
 The RLUK dataset
• Which data elements are available
• Linked external datasets
 The OpenSearch API
• Searching within the RLUK dataset
• RLUK dataset URIs and the API output

3. The Data Model

4. The Data Model
 RDA Element Vocabularies
• The most extensivelly used vocabularies in the RLUK dataset
• Used entensivelly in the properties of the Bibliographic Resources
 FRBRer model
• Used for context
• Not used for Item, Manifestation, Expression, Work
• The RLUK LOD data is derived from non-FRBR MARC data
 Europeana Data Model
• Used for Web Resources
 OWL 2 Web Ontology Language
• Used for linking to external datasets
• For linking duplicate Bibliographic Resources within the RLUK dataset
 Dublin Core Terms
• Used where more general semantics could/should be applied
 WGS84 Geo Positioning
 OAI ORE Terms
• Used for establishing the relations between Bibliographic and Web Resources

5. The Data Model
 Properties
• A large number of properties are available
describing the Bibliographic Resources and
their contextual information
• A complete list of the properties is available in
the Data Model documentation
• The frequency of availability of the properties
within the RLUK dataset, is available in the
Statistics documentation

6. Classes and URIs
 Bibliographic Resources
• http://data.theeuropeanlibrary.org/BibliograpicResource/...
 Web Resources
• The URIs are relative to the Bibliographic Resource
• http://data.theeuropeanlibrary.org/BibliograpicResource/...#webresource....
 Aggregations
• The URIs are relative to the Bibliographic Resource
• http://data.theeuropeanlibrary.org/BibliograpicResource/...#webresource....
 Other entities
• All other entities are encoded as RDF blank nodes
The LOD platform at The European Library serves all entites from the
URI of the Bibliographic Resources
• Web Resources and Aggregations have URIs that include fragments “#...”
• Other entities as RDF blank nodes

7. Available data in the RLUK
dataset
 Usage of classes

8. Available data in the RLUK
dataset
 Usage of properties

10. Available data in the RLUK
dataset
 Usage of data types

11. External LOD Datasets Linked To
 Links to external datasets linked are available for
the following:
• VIAF Virtual Union Authority File
• Geonames
• Library of Congress Subject Headings
• Library of Congress Children’s Subject Headings
• Library of Congress Classification
• data.bnf.fr
• Gemeinsame Normdatei
• Dewey Decimal Classification
• ISO639-2 Languages
• MARC Countries

12.  Availability of links
External LOD Datasets Linked To

13.  Availability of links
External LOD Datasets Linked To

14. Searching within the RLUK
dataset
 The European Library provides an OpenSearch
API for its complete dataset
• Queries may be narrowed to the RLUK dataset
 To use the API, registration in The
European Library portal is required
• An API key is provided to each registered
user
 The API outputs are in XML and JSON
• Each search result includes the LOD URI,
which can be used to access the RDF

15. Overview of the OpenSearch API
 In order to search within the RLUK dataset a parameter
should be specified:
• provider-id=P02023

16. Overview of the OpenSearch API
 In XML responses, the LOD URI is present in the first
dc:identifier element
 In JSON responses, a URI field contain the LOD URI

17. LOD Content Negotiation
 The responses to URIs are done according to LOD
Content Negotiation, as follows:
• Programmatic access to the URIs, or through data browsers,
should specify the RDF representation desired by specifying an
HTTP header “Accept”. The following RDF representations
(mime types) are available:
• text/turtle
• application/rdf+xml
• application/rdf+json
• text/n3
• text/rdf+n3
• application/x-binary-rdf

18. LOD Content Negotiation
 LOD Content Negotiation is supported in
data.theeuropeanlibrary.org.
 Any request to the URIs made with a web browser will
be redirected to the corresponding HTML page at the
portal.
 The web browser requests for the URIs are sent with the
HTTP header Accept:text/html or
Accept:application/xhtml+xml, therefore they are
redirected to the corresponding HTML page at the portal.
 For obtaining the RDF data for a URI with a web
browser, you may append the HTTP parameter
“format=rdf” to the URI.
http://data.theeuropeanlibrary.org/BibliographicResource/2000068736918?format=rdf

19. Thank you for your
attention
Contact:
nuno.freire@theeuropeanlibrary.org