A thesaurus is a list of terms used in databases to give consistent labels to articles which describe the same concept, but in a variety of ways. Using a thesaurus will save you time when searching a database and you can use it to collect keywords to use in other databases.
Why is a thesaurus useful?
You can use a thesaurus to collect search terms, including synonyms. These terms are discipline specific: you find the terminology used within a discipline, with the corresponding level of detail. For example: in the thesaurus of ERIC over 30 types of 'students' are distinguished! For a database for education research that level of detail makes sense.
The search terms found, can be used as input for search queries in databases without a thesaurus, for example Scopus or Web of Science.
In a database with a thesaurus, you can search directly from the list of thesaurus terms. This saves a lot of time! Try it yourself in the exercise below.
When you use a thesaurus, be aware that emerging concepts or locally used terms (for example related to government policy in a particular country) might not be available in a thesaurus. In some databases articles are added to the database first, and don’t get thesaurus terms immediately. That’s why you should combine a thesaurus search with a free text search.
The video How (and Why) to Use the APA Thesaurus When Searching PsycINFO via OvidSP (2.53) is interesting even if you don't use PsycINFO but would like to see how a database thesaurus works.
A thesaurus is a list of terms, structured hierarchically, showing
Thesauri are updated regularly and these updates reflect changes within a discipline and within society. Examples are ‘Big data', 'LGBTQ' and 'Digital gaming' which were added to the Thesaurus of Psychological Index Terms in 2019. The heading 'Zika virus' was introduced in the Medical Subject Headings in January 2016, in response to increased reports in the literature about the Zika virus outbreak.
Skillled indexers add these terms manually to the articles in a database.
Happiness in the Sociology Thesaurus used in Sociological Abstracts (left) and the Thesaurus of Psychological Index Terms used in PsycINFO (right) - in these examples no narrower terms are available.
Muller, F., van Zoonen, L., & de Roode, L. (2008). The integrative power of sport: Imagined and real effects of sport events on multicultural integration. Sociology of Sport Journal, 25(3), 387-401.
This article is indexed in several databases, including Sociological Abstracts and PsycINFO. The thesaurus terms assigned to this article differ per database:
The article in Sociological Abstracts: the thesaurus terms can be found behind Subject.
The same article in PsycINFO, here the thesaurus terms are called Subject Headings. In PsycINFO the * before a Subject Heading means that this is a main topic of the article. If you want to limit your results to these main topics, you can select the focus option in the thesaurus search in PsycINFO.