Search terms

A search term is any word that you use in searching information. It can be a natural language word or so-called subject term found in a database. When you search for information, these words are those that identify and describe the contents of items (articles, books etc.). In a database these (key)words can be found e.g. in the title, abstract, author, text, etc.

Differences between natural language and subject terms are many.
Compare the differences between natural language and subject terms and their utilisation in databases.

Watch the video Subject headings vs keywords (1:55) by Wellington Medical and Health Sciences Library  (the link opens in YouTube in a new tab).

See below on example the word lung cancer in the Medical Subject Headings (MeSH) thesaurus. MeSH is the National Library of Medicine controlled vocabulary thesaurus used for indexing articles for MEDLINE/PubMed:

Example of the PubMed database and its thesaurus.
A thesaurus directs you to use the controlled subject terms as well as gives you an idea of the broader and narrower context of the term.

In the MeSH Lung Neoplasms is the preferred index term to use when you search for lung cancer. Lung cancer is so-called Entry terms. Entry terms are synonyms, alternate forms or other closely related terms.

What if you cannot find a subject term(s) for your topic?

In that case, you just have to use natural language words.

  • Not all disciplines/databases have controlled vocabulary or Thesaurus. Some databases use the author’s own keywords (the words that author used to describe the article).
  • Especially very specific or a new subject do not have yet a Subject Term.

Another way to find subject terms:

  • Start with a basic search, using words/phrases that describe your topic.
  • Browse the results; choose two or three that are relevant.
  • Look at the Subject or Descriptor field and note the terms used.
  • Redo your search using those terms.

Searching is an iterative process. There is no one way to conduct a search. You may notice that the search terms you have initially chosen are not the best and you have to modify and re-run the search using different terms.

(8/2023 RH)

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