The LC Linked Data Service is an initiative of the
Library of Congress
The Library of Congress (LOC) is the research library that officially serves the United States Congress and is the ''de facto'' national library of the United States. It is the oldest federal cultural institution in the country. The librar ...
linked data
In computing, linked data (often capitalized as Linked Data) is structured data which is interlinked with other data so it becomes more useful through semantic queries. It builds upon standard Web technologies such as HTTP, RDF and URIs, but ...
.
It is commonly referred to by its URI: id.loc.gov.
The first offering of the LC Linked Data Service was the
Library of Congress Subject Headings
The Library of Congress Subject Headings (LCSH) comprise a thesaurus (in the information science sense, a controlled vocabulary) of subject headings, maintained by the United States Library of Congress, for use in bibliographic records. LC Subject ...
(LCSH) dataset, which was released in April 2009.
Datasets
*
Library of Congress Subject Headings
The Library of Congress Subject Headings (LCSH) comprise a thesaurus (in the information science sense, a controlled vocabulary) of subject headings, maintained by the United States Library of Congress, for use in bibliographic records. LC Subject ...
(LCSH)
* Library of Congress Name Authority File (LCNAF)
*
Library of Congress Classification The Library of Congress Classification (LCC) is a system of library classification developed by the Library of Congress in the United States, which can be used for shelving books in a library. LCC is mainly used by large research and academic librar ...
—because LC Classification uses a different MARC format than LC Authorities, mapping LC Classification to MADS/RDF was more difficult than mapping LCSH or LCNAF.
* Library of Congress Thesaurus for Graphic Materials
* Various MARC codes
* Various preservation vocabularies
SKOS
Simple Knowledge Organization System (SKOS) is a W3C recommendation designed for representation of thesauri, classification schemes, taxonomies, subject-heading systems, or any other type of structured controlled vocabulary. SKOS is part of ...
where appropriate, but also uses its own ontology to describe classification resources and relationships more accurately. All records are available individually via
content negotiation
Content negotiation refers to mechanisms defined as a part of HTTP that make it possible to serve different versions of a document (or more generally, representations of a resource) at the same URI, so that user agents can specify which version fi ...
RDF/XML
RDF/XML is a syntax,RDF/XML Syntax Specification N-Triples, and
JSON
JSON (JavaScript Object Notation, pronounced ; also ) is an open standard file format and data interchange format that uses human-readable text to store and transmit data objects consisting of attribute–value pairs and arrays (or other s ...
.
Each vocabulary is also available to download in its entirety. Id.loc.gov does not currently provide a SPARQL endpoint.
Uses
All of LCSH are crosslinked with (), an authority file from the
Bibliothèque nationale de France
The Bibliothèque nationale de France (, 'National Library of France'; BnF) is the national library of France, located in Paris on two main sites known respectively as ''Richelieu'' and ''François-Mitterrand''. It is the national reposito ...
.
Technical aspects
The id.loc.gov site initially used a fairly lightweight Python program to serve linked data.
See also
*
Authority control
In information science, authority control is a process that organizes information, for example in library catalogs, by using a single, distinct spelling of a name (heading) or a numeric identifier for each topic. The word ''authority'' in ''aut ...
*
BIBFRAME BIBFRAME (Bibliographic Framework) is a data model for bibliographic description. BIBFRAME was designed to replace the MARC standards, and to use linked data principles to make bibliographic data more useful both within and outside the library c ...
* (PND)
*
Virtual International Authority File
The Virtual International Authority File (VIAF) is an international authority file. It is a joint project of several national libraries and operated by the Online Computer Library Center (OCLC).
History
Discussion about having a common ...