Framing your research question

Question frameworks are used to help you turn your research question into the searches you will need for databases and search engines

PECO and its variations

PECO is a variant of PICO which looks at Exposure instead of Intervention. It is also used in formulating clinical questions.

  • How is your population defined? (e.g. age, gender, ethnic group …)
  • What has your population been deliberately or inadvertently exposed to?
  • What are you comparing this with, e.g. a different level of exposure? (It’s ok to leave this one blank if you are not doing a comparison)
  • Which result(s) are you focusing on or measuring?
  • What are you hoping to improve?


Other variables that can be added to this PICO framework are:

  • What is the follow up schedule?
  • What is the duration of the exposure?
  • What is the follow up schedule?
  • Is this a longitudinal study?
  • Which reported results are you looking for in the literature on your topic?


Variant frameworks:

  • PECODR = Population, Exposure, Comparison, Outcome, Duration, Results
  • PECOT = Population, Exposure, Comparison, Outcome, Timeframe
  • PEO = Population, Exposure, Outcome