katalogtjenester

Katalogtjenester are services that provide centralized access to metadata and search functionality for organized collections, typically within libraries, archives, museums and other cultural heritage institutions. They enable users to locate items by title, author, subject, or identifier and to view holdings status, location, and loan information. Katalogtjenester may be local, based on a single institution's catalog, or federated, linking multiple catalogs into a unified search interface often referred to as a discovery layer or union catalog.

These services rely on metadata standards and exchange protocols to describe items and share data. Common schemas include MARC, Dublin Core, and newer models like BIBFRAME; identifiers such as ISBN, ISSN, and DOI enhance retrieval and disambiguation. Data may be exposed via protocols and interfaces such as Z39.50, SRU/SRW, OAI-PMH for harvesting, and RESTful or OpenSearch APIs for programmatic access. Interfaces typically support facets, relevance ranking, and features such as hold or request, renewal, and linking to full text or digital copies.

Katalogtjenester are often integrated within a library management system or deployed as a discovery layer that indexes catalog records, holdings, and link resolvers. They facilitate interoperability through authority control, linked data, and connections to external catalogs, enabling interlibrary loans and resource sharing. Ongoing developments emphasize improved user experience, mobile access, accessibility, and adherence to international standards to enhance discoverability of bibliographic resources across institutions.