StATS: A nice definition of anecdotal evidence (created 2005-10-24).

Robert Todd Carroll, author of The Skeptics Dictionary [BookFinder4U link] and creator of the website Skepdic.com, mentioned in a recent newsletter that he has updated his definition for anecdotal evidence. He points out that anecdotes are unreliable because they  are

prone to contamination by beliefs, later experiences, feedback, selective attention to details, and so on.

and although these are "scientifically worthless", their vivid details make them popular. But Dr. Carroll wisely does not totally rule out their use. A physician, he explains should listen to anecdotal evidence from individual patients, but has to be careful.

But the physician cannot be selective in listening to testimony, listening only to those claims that fit his or her own prejudices.

Dr. Carroll also provides some other good definitions for related terms, and I am including the first sentence from each definition since they are so well written.

A good book that Dr. Carroll cites, and which I have mentioned on several of my webpages is:

Dr. Carroll also mentions another book, co-authored by Gilovich, "Why Smart People Make Big Money Mistakes and How to Correct Them: Lessons From the New Science of Behavioral Economics" [BookFinder4U link] that I have not yet read, but which sounds very interesting.

This page was written by Steve Simon while working at Children's Mercy Hospital. Although I do not hold the copyright for this material, I am reproducing it here as a service, as it is no longer available on the Children's Mercy Hospital website. Need more information? I have a page with general help resources. You can also browse for pages similar to this one at Category: Critical appraisal.