The YSA is a general thesaurus in Finnish which covers all fields of research and knowledge, which contains the most common terms and geographical names used in content description.
YSA is a tool for providing index terms for printed and electronic materials as well as subject-based information retrieval. The thesaurus works as a shared language between information depositaries and searchers, which improves the ease of finding information.
YSA contains approximately 33,000 terms (of which 6,000 are geographical names) and it grows by approximately 1,000 terms each year. The thesaurus has a link to the corresponding term in the Swedish-language Allärs thesaurus and the corresponding concept in the YSO ontology.
YSA is also used as a basic thesaurus when drawing up specialised thesauri for various fields.
- Free of charge
YSA has been used in databases since 1987.
Allärs is YSA's Swedish translation.
The General Finnish Upper Ontology YSO has been developed on the basis of YSA.
- Private individuals
The thesaurus is used above all in the databases of libraries, archives and museums.
The National Library of Finland
- Service is developed as part of basic operation of National Library