OCLC has published bibliographic linked data for the most widely held works in WorldCat. This downloadable file—representing nearly 1.2 million resources—contains approximately 80 million linked data “triples,” the term for the most granular relationship possible between discrete pieces of information.
“This is an important step for libraries and linked data,” said Richard Wallis, OCLC Technology Evangelist. “Organizations wishing to develop linked data services can experiment with this data set before going into full development. They’ll also be able to stress-test new services using a very large and important set of up-to-date, linked library data. We are really interested to see what people will do with this data.”
The linked data is provided as RDF serialization, and uses the Schema.org ontology as well as library extensions to Schema.org that OCLC has been working on with members and partners over the last year. It is being made available, under an ODC-BY data license, in a single, 1-gigabyte, compressed (GZip) file, which can be downloaded from here.
While WorldCat contains bibliographic records for more than 275 million items, the choice was made to select the most widely held materials for this release in order to help keep the file at a manageable size. Jeff Young, the OCLC Research software architect who did much of the modeling necessary to generate the linked data file, explains, “To make the cut, a resource had to be held by at least 250 libraries. This seemed to us to be a good balance between providing widely useful data while making it reasonably manageable for most uses.”
“OCLC expects that the file will be useful as a source of raw data. Information about works, authors and publishers can be dissected and recombined in this format much more easily,” Mr. Young said. “This provides a great tool for researchers in library science, as well as those who may want to do cultural, historical, sociological or other research based on the rich data libraries have been contributing to WorldCat for decades.”
Mike Teets, OCLC Vice President for Innovation, added, “This release will make it easier for the wider linked data community—commercial providers, retail organizations, researchers and scholars—to include library information in their workflows. It will also make it easier for libraries to do the same in reverse, connecting their materials back to the Web through services that people use every day.”
In June 2012, OCLC added Schema.org tags to WorldCat.org records, improving the way in which library information is represented to search engines. OCLC has also developed linked data resources for the Dewey Decimal Classification System, FAST (Faceted Application of Subject Terminology) and the VIAF (Virtual International Authority File) service. The release of these 1.2 million records as linked data is the next step in OCLC’s linked data strategy.
“We are focusing our efforts on getting WorldCat data into accessible forms for local experimentation and development,” explained Mr. Teets, “with the objective that this will promote libraries as a trusted hub for linked data.”
“This really is an effort that requires input from many sources,” continued Mr. Teets. “Designing and generating linked data in this way requires many vocabulary and modeling choices, and we want to get as much input and commentary from the library community as possible.”