I have been working for some years on specification and implementation of several APIs and exchange formats for data used in, and provided by libraries. Unfortunately most existing library standards are either fuzzy, complex, and misused (such as MARC21), or limited to bibliographic data or authority data, or both. Libraries, however, are much more than bibliographic data – they involve library patrons, library buildings, library services, library holdings, library databases etc.
During the work on formats and APIs for these parts of library world, Patrons Account Information API (PAIA) being the newest piece, I found myself more and more on the way to a whole library ontology. The idea of a library ontology started in 2009 (now moved to this location) but designing such a broad data model from bottom would surely have lead to yet another complex, impractical and unused library standard. Meanwhile there are several smaller ontologies for parts of the library world, to be combined and used as Linked Open Data.
In my opinion, ontologies, RDF, Semantic Web, Linked Data and all the buzz is is overrated, but it includes some opportunities for clean data modeling and data integration, which one rarely finds in library data. For this reason I try to design all APIs and formats at least compatible with RDF. For instance the Document Availability Information API (DAIA), created in 2008 (and now being slightly redesigned for version 1.0) can be accessed in XML and in JSON format, and both can fully be mapped to RDF. Other micro-ontologies include:
- Document Service Ontology (DSO) defines typical document-related services such as loan, presentation, and digitization
- Simple Service Status Ontology (SSSO) defines a service instance as kind of event that connects a service provider (e.g. a library) with a service consumer (e.g. a library patron). SSSO further defines typical service status (e.g. reserved, prepared, executed…) and limitations of a service (e.g. a waiting queue or a delay
- Patrons Account Information API (PAIA) will include a mapping to RDF to express basic patron information, fees, and a list of current services in a patron account, based on SSSO and DSO.
- Document Availability Information API (DAIA) includes a mapping to RDF to express the current availability of library holdings for selected services. See here for the current draft.
- A holdings ontology should define properties to relate holdings (or parts of holdings) to abstract documents and editions and to holding institutions.
- GBV Ontology contains several concepts and relations used in GBV library network that do not fit into other ontologies (yet).
- One might further create a database ontology to describe library databases with their provider, extent APIs etc. – right now we use the GBV ontology for this purpose. Is there anything to reuse instead of creating just another ontology?!
The next step will probably creation of a small holdings ontology that nicely fits to the other micro-ontologies. This ontology should be aligned or compatible with the BIBFRAME initiative, other ontologies such as Schema.org, and existing holding formats, without becoming too complex. The German Initiative DINI-KIM has just launched a a working group to define such holding format or ontology.