Subject terms and text words

For your literature search to be complete, you should if possible use both text words and subject terms when you search for information for a literature study. What is the difference between a text word and a subject term?

Text words

The search words that you’ve found on your own from your research question/problem are called text words. You can search for these in all databases.
Text words are words you choose yourself, as opposed to subject terms, which you look up in the database. We select text words for each element of the research question/problem. Example, exercise: exercise, physical activity, swimming, yoga.
To the greatest extent possible, you should use the same words in the databases that you choose to search in. If the text word is changed between databases, you break with the structured approach to the literature search.
In order to make your search more precise, you can define where you want to search for your search terms in the database’s documents (articles, books, reports, etc.). You can for instance search in the article’s title and abstract. Doing this will elicit results where the word is so important that it features in the title and/or abstract of the article.

Subject terms

Subject terms can be found in many databases, but not all. Some databases like Web of Science and Scopus do not have thesauri or subject terms.
Subject terms are searchable ‘tags’ that feature on all literature that is indexed in the database and are used to explain what the article is about.
The subject terms are organized in a list, a so-called thesaurus, which is used to describe the literature in the database.
Subject terms vary between databases and must therefore be adapted to the database that you are searching in.
Subject terms make it easier to find articles on the same subject, even when the authors may have used divergent terminology (different words) in their articles.
In some cases, there may be several subject terms within one component of your research question/problem.
There aren’t subject terms for all themes. If you cannot find a subject term that fits, it is important to work thoroughly with your text words.

Central aspects of subject terms:

Hierarchical—in other words, organized in a system from general to specific. Example: Hand, finger, thumb.
Standardized—one subject term for one concept (the subject term exercise covers terms such as physical activity, exercise, working out, …)

Want to know more? See the library’s online course for Litteratursøk i medisinske databaser:

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