In the context of information retrieval, a thesaurus (plural: "thesauri") is a form of controlled vocabulary that seeks to dictate semantic manifestations of metadata in the indexing of content objects.
A thesaurus serves to minimise semantic ambiguity by ensuring uniformity and consistency in the storage and retrieval of the manifestations of content objects.
Wherever there have been large collections of information, whether on paper or in computers, scholars have faced a challenge in pinpointing the items they seek.
The most notable innovations since TEST have been: (a) Extension from monolingual to multilingual capability; and (b) Addition of a conceptually organized display to the basic alphabetical presentation.
Here we mention only some of the national and international standards that have built steadily on the basic rules set out in TEST: The most clearly visible trend across this history of thesaurus development has been from the context of small-scale isolation to a networked world.
This means that the semantic conceptual expressions of information bearing entities are easier to locate due to uniformity of language.
Unlike a general thesaurus that is used for literary purposes, information retrieval thesauri typically focus on one discipline, subject or field of study.