Each subject area has its own special terminology. When used in the context of a research database, it is called a controlled vocabulary. This makes searching easier and more successful. By standardizing the words or phrases used to represent concepts, you don't need to try and figure out all the ways different authors could refer to the same concept.
The opposite of controlled vocabulary is natural language, which you might know as keyword. You were taught to search the library databases using keywords and synonyms in the English Composition (ENG1100) course. We are taking research to a higher, and more specific, level by using controlled vocabulary.
It is important to locate the thesaurus in each research database and learn the controlled vocabulary used in your subject area for that particular database.
Noun. (plural thesauri or thesauruses) A publication, usually in the form of a book, that provides synonyms (and sometimes antonyms) for the words of a given language. (Wiktionary)
Did you know? In research databases, controlled vocabularies are usually called a thesaurus. Go figure.
Controlled vocabularies provide a way to organize knowledge for subsequent retrieval. They are used in subject indexing schemes, subject headings, thesauri, taxonomies and other knowledge organization systems. Controlled vocabulary schemes mandate the use of predefined, authorized terms that have been preselected by the designers of the schemes, in contrast to natural language vocabularies, which have no such restriction. (Wikipedia)
Did you know? Hashtags are a form of controlled vocabulary. #controlledvocabulary
noun. plural: keywords.
Did you know? Keywords are natural language with no control involved. You never know what you're going to get.