Data Model and API
Nuno Freire
RLUK Hack DayLondon, 14th of May 2014
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
The Data Model
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
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
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
Available data in the RLUK dataset
Usage of classes
Available data in the RLUK dataset
Usage of properties
Available data in the RLUK dataset
Usage of data types
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
Availability of links
External LOD Datasets Linked To
Availability of links
External LOD Datasets Linked To
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
Overview of the OpenSearch API
In order to search within the RLUK dataset a parameter should be specified:• provider-id=P02023
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
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
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
Thank you for your attention
Contact:[email protected]
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