Examples of Knowledge Organization System (KOS)
This section offers examples of Knowledge Organization Systems (KOSs) that can act as pre-existing tools for indexing documents or for structuring knowledge within a particular domain.
Knowledge Organization Systems vary from simple lists of terms like glossaries to hierarchical structures such as bibliographic classifications and taxonomies. These systems may also show other semantic relationships, as seen in thesauri, which include synonymity and associated relationships. Ontologies go further by including functional relationships and properties of concepts. In all cases, the naming of concepts must be standardised (controlled) to ensure consistency in idexing/tagging and maximise predictabilty in searching.
The diagram below illustrates the range of semantic richness progressing from simple lists of terms to representations of reality.
Most of the examples listed below are sourced from the BARTOC registry, which provides a rich array of controlled vocabularies.
BARTOC - Basel register of KOS ranging from glossaries, subject heading, classification schemes, Thesauri, ontologies, classifications and terminologies.
Online thesauri and autority files collected by the American Society for Indexing
NATO's glossary of terms concerning the saftey and suitability of service for munitions, explosives and related products
Medical Subject Headings by the National Library of Medicine
Universal Decimal Classification (UDC) - is a system for classifying all fields of knowledge in any medium.
Dewey Decimal Classification (DDC) - is a system used by libraries to arrange materials by subject.
Library of Congress Classification (LCC) - is a system first developed to organise the book collections of the Library of Congress. Over the years, the system has been adopted by other libraries as well, especially large academic libraries in the United States.
Bliss Classification (BC2) - The Bibliographic Classification (BC2 or Bliss) is the leading example of a fully faceted classification scheme. It provides a detailed classification for use in libraries and information services of all kinds, having a broad and detailed structure and order.
AGROVOC - Multilingual thesaurus of the food and Agriculture Organization of the United Nations
CABI Thesaurus- Thesaurus of CABI, an international not-for-profit organization that improves people’s lives worldwide by providing information and applying scientific expertise to solve problems in agriculture and the environment.
ERIC Multimedia Thesaurus - a KOS covering educational concepts and showing how to use it to index documents.
EUROVOC - EuroVoc is the EU's multilingual and multidisciplinary thesaurus. It contains keywords, organized in 21 domains and 127 sub-domains, which are used to describe the content of documents in EUR-Lex.
The Agrontology - The Agrontology is a description vocabulary defined in the Web Ontology Language (OWL) providing a set of domain-specific properties for agri-food related concepts. It is maintained by the Food and Agriculture Organization of the United Nations (FAO) as a living ontology, enriched and improved based on users' feedback.