Our friends at Compound Interest (a fantastic website and a useful resource for science educators and communicators) created a very handy infographic to provide people with A Rough Guide to the Types of Scientific Evidence.  Being able to evaluate evidence behind a claim is important, but scientific evidence comes in a variety of forms.  Here, different types of scientific evidence are ranked and described, particularly those related to health and medical claims.

From the weakest evidence to the strongest, they are…

  • Anecdotal or “Expert” Opinions
  • Animal and Cell Studies (experimental)
  • Case Reports and Case Series (observational)
  • Case Control Studies (observational)
  • Cohort Studies (observational)
  • Randomized Controlled Trials (experimental)
  • Systematic Review

Click the infographic for a larger, more legible view.

A Rough Guide to Scientific Evidence

Source:  Compound Interest