OCLC exposes Work Identifiers
By Janifer Gatenby, OCLC
OCLC has extended the xOCLCNUM API to include the OCLC work identifiers (OWIs) in addition to OCLC record identifiers (OCNs) that correspond to manifestations. For several years now, WorldCat has been organised according to the FRBR model[1] that allows grouping of various editions of publications (e.g. reprints, translations, performances, digitized copies) into works. Sometimes users require particular manifestations and sometimes not, so it is desirable to cater for both needs by allowing navigation from works to manifestations and vice versa.
The expanded xOCLCNUM service now returns variant manifestation level identifiers (OCN, ISBN and LCCN) and the OWI. In addition to starting with an OCN, ISBN or LCCN as an entry point into the API, OWI is now permitted as a starting point. For details and examples, see the xOCLCNUM web service documentation page [2].
Systems using the service are able to expand displays using the identifiers returned in the API: for example, the API could be called behind a button labeled "find alternative editions". The service could also be used by systems wishing to cluster search results by work, though performance requirements may preclude the option for clustering larger result sets on the fly. In anticipation of this, OCLC has a prototype service to complement the API that provides a machine readable table of OCN and OWI specific to a catalogue's subset of WorldCat. The OCN / OWI identifier combination is important as a means of linking records for particular resources as they occur in multiple databases. Only 30% of resources in WorldCat have an international identifier such as ISBN, and a recent study has shown that this applies to recently published materials as well as those published before international identifiers came into being in the second half of the 20th century. For example, in between 1970 and 1990, there are on average 9 million records per decade without international identifiers. OCLC is continuing to evolve its identifier services and encouraging adoption of its identifiers by external databases. In this way the identifiers can be used for navigating among web databases, without necessarily passing via OCLC, acting as a linchpin for mash-ups.
[1] http://www.ifla.org/en/publications/functional-requirements-for-bibliographic-records
[2] http://xisbn.worldcat.org/xisbnadmin/xoclcnum/api.htm
OCLC has extended the xOCLCNUM API to include the OCLC work identifiers (OWIs) in addition to OCLC record identifiers (OCNs) that correspond to manifestations. For several years now, WorldCat has been organised according to the FRBR model[1] that allows grouping of various editions of publications (e.g. reprints, translations, performances, digitized copies) into works. Sometimes users require particular manifestations and sometimes not, so it is desirable to cater for both needs by allowing navigation from works to manifestations and vice versa.
The expanded xOCLCNUM service now returns variant manifestation level identifiers (OCN, ISBN and LCCN) and the OWI. In addition to starting with an OCN, ISBN or LCCN as an entry point into the API, OWI is now permitted as a starting point. For details and examples, see the xOCLCNUM web service documentation page [2].
Systems using the service are able to expand displays using the identifiers returned in the API: for example, the API could be called behind a button labeled "find alternative editions". The service could also be used by systems wishing to cluster search results by work, though performance requirements may preclude the option for clustering larger result sets on the fly. In anticipation of this, OCLC has a prototype service to complement the API that provides a machine readable table of OCN and OWI specific to a catalogue's subset of WorldCat. The OCN / OWI identifier combination is important as a means of linking records for particular resources as they occur in multiple databases. Only 30% of resources in WorldCat have an international identifier such as ISBN, and a recent study has shown that this applies to recently published materials as well as those published before international identifiers came into being in the second half of the 20th century. For example, in between 1970 and 1990, there are on average 9 million records per decade without international identifiers. OCLC is continuing to evolve its identifier services and encouraging adoption of its identifiers by external databases. In this way the identifiers can be used for navigating among web databases, without necessarily passing via OCLC, acting as a linchpin for mash-ups.
[1] http://www.ifla.org/en/publications/functional-requirements-for-bibliographic-records
[2] http://xisbn.worldcat.org/xisbnadmin/xoclcnum/api.htm
Hi Jennifer,
nice technical approach. But central commercial driven identifiers (or in other words identifiers where I have to pay any fee to use/ reuse them) will in my eyes always have wide acceptens problem (that can be maybe learned from DOI) in the library world. Real standards must be like ISO Standards totaly free and open for everybody. So a key question will be should only a nice technical approach for OCLC members or can it get maybe more?
Patrick
Hi Patrick. OCLC encourages the use of its identifiers and as a result the use of OCLC identifier web services, xISBN, xISSN and xOCLCNUM, is free up to a certain threshold. OCLC places no restrictions on the re-use of its own identifiers which can be used by member libraries, non member libraries and non library organizations alike. Thus the OCN (manifestation level identifier) and the OWI (work level identifier) can serve to connect the same resource across multiple web sites, particularly in the absence of any other well known and shared identifier. Janifer