Trends and issues in establishing interoperability among knowledge organization systems

This report analyzes the methodologies used in establishing interoperability among knowledge organization systems (KOS) such as controlled vocabularies and classification schemes that present the organized interpretation of knowledge structures. The development and trends of KOS are discussed with reference to the online era and the Internet era. Selected current projects and activities addressing KOS interoperability issues are reviewed in terms of the languages and structures involved. The methodological analysis encompasses both conventional and new methods that have proven to be widely accepted, including derivation/modeling, translation/adaptation, satellite and leaf node linking, direct mapping, co-occurrence mapping, switching, linking through a temporary union list, and linking through a thesaurus server protocol. Methods used in link storage and management, as well as common issues regarding mapping and methodological options, are also presented. It is concluded that interoperability of KOS is an unavoidable issue and process in today's networked environment. There have been and will be many multi-lingual products and services, with many involving various structured systems. Results from recent efforts are encouraging.