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PBHL 150- Dolan- Fall 2025

Searching for articles

Are "anti-vaxxers" influenced by Instagram?

Search engines

Types of searches

Balancing Recall and Precision

Searching is an iterative process.  When completing a database search, it is important to achieve a balance between precision (or specificity) and recall (or sensitivity).

  • Precision (or specificity):is "the proportion of citations in a given search that are relevant to the search question”. Precision is important if the intended purpose of the literature search is to get background information on the topic or an overview of the subject area. For most student papers, precision is the goal. Retrieving all primary literature is not necessary.
  • Recall (or sensitivity) is "the proportion of relevant citations in a given search among the total number of relevant citations available in the bibliographic database". Recall is important if the intended purpose of the literature search is to locate primary literature to support a grant application, publication, or systematic review or to protect human research subject(s) from adverse events or harm. In this case, identifying all primary literature is necessary.

The following table outlines different search techniques that can increase precision or recall of the literature search.

Too Many Results (increase precision or specificity) Too Few Results (increase recall or sensitivity)
Use major subject terms Use the broad subject terms
Use the "focus" option, if available Use the "explode" option, if available
Select more specific, narrower subject headings Check similar/related articles for additional terms
Use appropriate subheadings for each subject heading Do not use subject heading’s subheadings
Decrease the number of keywords, synonyms Use the database's search fields to identify keywords
Precision can be enhanced by decreasing the use of the Boolean operator "OR". This eliminates synonyms or like concepts. Include alternate spellings, variant endings
Precision can also be increased by adding concepts with the Boolean operator "AND". Increasing recall requires greater use of synonyms and the Boolean operator "OR", as well as a reduction in the use of the Boolean operator "AND".
Searching for precision should result in retrieving many relevant citations and very few irrelevant citations. Be aware that recall will have an inverse effect on the performance of the literature search by also retrieving many irrelevant citations.

Adapted from UT Southwestern Health Sciences, https://utsouthwestern.libguides.com/responsible-lit-search/refine

Setting up appointment with Candice

You can set up a consultation with any of my colleagues at https://libcal.swem.wm.edu/appointments/wm-libraries  but if you want to meet with me specifically, you can see my availability at: calendly.com/cbsmall