How do I find and use controlled vocabulary search terms?

In many databases, articles are indexed with subject headings or controlled vocabulary search terms meant to make it easier to find articles about a certain subject. PubMed, for instance, uses the controlled vocabulary list MeSH (Medical Subject Headings).

You can find controlled search terms in many ways. One way is to search directly in a given database’s thesaurus. You can also find out which search terms were used to index your key articles. 

Controlled search terms are usually hierarchically organized, with a superior – broader – term, and a subordinate – narrower – term. In the thesaurus you may also find referrals to related terms. One tip is to use both broader, narrower and related terms, in order to ensure that you’re getting all the relevant subject headings into your search. 

The default setting in most databases is the automatic explosion of subject headings, that is, the search will include subordinate terms. This is often useful, but sometimes it can be more helpful to turn this setting off and search for a term without explosion.