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Research Guides@Tufts

NUTR 369: Systematic Reviews

What is a Controlled Vocabulary?

›“… a carefully selected list of words and phrases, which are used to tag units of information (document or work) so that they may be more easily retrieved by a search…Controlled vocabularies reduce ambiguity inherent in normal human languages where the same concept can be given different names and ensure consistency.” -Wikipedia


  • Created and edited by a "governing body" to introduce new official terms, phase out old ones, and add new mapping for concepts
  • Reduces the burden on researchers of a database by mapping human language synonyms to the official term
  • Searching by a concept or idea, rather than by the presence of a string of letters

Other Controlled Vocabularies

There are thousands of thesauri and controlled vocabularies. Often there are multiple available for one general topic area. The following examples will give you a small idea of the variation and scope of controlled vocabularies.



Medical Subject Headings in PubMed

The Medical Subject Headings (MeSH) is one example of a controlled vocabulary. It can be used while searching the MEDLINE database via PubMed or OVID.

  • Created and maintained by the National Library of Medicine
  • Subject headings are applied to every article indexed in PubMed to identify key topics of the publication
  • Reduces need to think of synonyms and natural language descriptions 
  • MeSH database allows you to search for the controlled term using keywords and build a search to use in PubMed


An Introduction to Medical Subject Headings from Tufts HHSL on Vimeo.