Frequently asked questions 5 – How and where to find search terms?


  • Where do the search terms come from?
  • How can I know which words I should use in searching?
  • Where can I find search terms?

The words you use as search terms can come from:

  • your brain; what words do you use to talk or to write about your topic?
  • dictionaries; especially when you need to check the spelling; you can use e.g. the MOT online dictionaries (authentication needed)
  • handbooks and textbooks; especially when you want to check the definition
  • the books and articles you have already found; what terms and expressions do they use?
  • thesauri; the controlled vocabularies of the databases, for example MeSH (Medical Subject Headings) that is used in many health related databases in indexing the contents

It is worth the time and the effort to pay attention to choosing your search terms, as well as thinking about how to combine them. That will save you time (and nerves) later. One might want just to write them down, someone else likes to draw a mind map, and another one organises them in a chart. Choose your own style.

mind map image

By: Tuulevi Ovaska, Head of Services, Kuopio University Hospital Medical Library, University of Eastern Finland Library


Frequently asked questions 2 – Truncation

Questions about truncating search terms when searching databases:

  • Why is it necessary to truncate search terms?
  • How should I truncate my term?
  • What truncation mark should be used?

You do not always have to truncate your search terms but…

  • robots (search engines) only search for character strings, not for meanings
  • most terms have singular and plural forms, and also genetives


  • truncated patient* retrieves all these: patient, patients, patient’s
  • not truncated patient retrieves only patient
  • truncated child* retrieves child, children, child’s children’s
  • not truncated child retrieves only child

Different databases use different truncation marks. The most common are asterisk * and question mark ?. Check the database’s manual/FAQ if * does not seem to work. In PubMed, Cochrane Library and Scopus truncate using *. In Josku truncate using ?.

truncation marks

There are also irregular plurals so that the singular and plural forms are different in a way that truncation does not work.

For example:

  • foot/feet
  • mouse/mice
  • tooth/teeth
  • woman/women

In some databases it is possible to use so called wild cards and search for e.g. wom*n, but in many databases you have to search singular and plural combined with OR.

For example:

  • foot OR feet
  • mouse OR mice
  • tooth OR teeth
  • woman OR women

There are also irregular plurals that can be search by truncating.

For example:

  • criteri* retrieves singular criterion and pluralcriteria
  • nucle* retrieves singular nucleus and plural nuclei (and also nuclear, nucleic, nucleoid, nucleon…)
  • analys* retrieves singular analysis and plural analyses (and also analysand and analyst)
  • phenomen* retrieves singular phenomenon and plural phenomena (and also e.g. phenomenology)

Watch a video in YouTube about truncation.

By: Tuulevi Ovaska, Head of Services, Kuopio University Hospital Medical Library, University of Eastern Finland Library