Developing the search: recall & relevance


2004 version 2
24 May 2004

To maximise recall (sensitivity, or comprehensiveness)
  • use MeSH terms with keywords
  • explode MeSH terms
  • select the All Subheadings option
  • incorporate synonyms using or
  • use truncation ($) and wildcards (#, ?)
  • refine the search by looking for additional suitable search terms (look at records that give a good match)
  • search as far back in time as possible
  • consider other databases
    To optimise relevance (specificity)
  • use MeSH headings only rather than MeSH with keywords
  • make the MeSH headings as specific as possible
  • focus MeSH terms
  • use MeSH subheadings
  • add in other terms (using and) to represent extra concepts in the question
  • use limits (including filters)
  • consider title-only searching
    A good balance between recall and relevance is often achieved by using MeSH headings plus title field searching. Inconsistently indexed yet relevant records can be retrieved using title keywords without swamping the search result. Unless you need to be comprehensive, using keywords too liberally with MeSH headings can cancel out the advantages that the controlled vocabulary of the MeSH terms bring.

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    © British Medical Association 2008

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