Pitfalls of Thinking: Anecdotal Evidence

Relying on anecdotes is intuitively a bad idea, but why? When we rely on a very small sample of outcomes, the results may not represent the population as a whole. This is the basis of gambling, alternative medicine, and it's something that science based medicine has very carefully removed from the process. We trust statistics because they are more descriptive and predictive than anecdotes.

J Clin Epidemiol. 2008 Dec;61(12):1197-204. Epub 2008 Oct 1.
The conclusions on the effectiveness of homeopathy highly depend on the set of analyzed trials.
http://www.ncbi.nlm.nih.gov/pubmed/18834714

This was a comment on:
Lancet. 2005 Aug 27-Sep 2;366(9487):726-32.
Are the clinical effects of homoeopathy placebo effects? Comparative study of placebo-controlled trials of homoeopathy and allopathy.
http://www.ncbi.nlm.nih.gov/pubmed/16125589

QualiaSoup's elegant video on anecdotes (a personal favorite):
http://www.youtube.com/watch?v=NPqerbz8KDc

Dr. Wikipedia:
http://en.wikipedia.org/wiki/Anecdotal_evidence

Category:

Education

Tags:

• Anecdotal
• evidence
• alternative
• medicine
• homeopathy
• chiropractic
• clinical
• trials
• iatrogenesis
• reiki
• chi
• gambling
• fallacy
• statistics
• population
• size

[applefrog111]

But I once knew an anecdote that was correct.

[C0nc0rdance]

@applefrog111

My grandfather used anecdotes every day of his life to make decisions, and he lived to be 117. My father swore by anecdotes, and he's the King of France today!

[samthejokerman]

Beautiful job as always, c0nc0rdance!

[superustipak]

Which 3 idiots disliked this video?

[applefrog111]

@C0nc0rdance

My friend told me that he once slipped in a McDonald's on his way to his job at Wendy's.

[FiveZylinderRacing]

This sums up why Im smart and many others are not so smart. You can apply this to Religion and all of the other crock of shit claims made by low IQ having peoples =)

[sol6erino]

Large randomised controlled trials are beyond the financial resources of most natural forms of medicine. They are a great tool for organised medicine to spread this kind of philosophy. In the case of Chiropractic the N.Z. Royal Commission into Chiropractic, the highest form of legal inquiry after extensive examination and interviews of thousands of citizens found there was adequate evidence for Chiropractic to be included into the national health system. This was vigorously opposed by the A.M.A.

[R18111983]

Poker is NOT gambling! :)

[tskasa1]

@brmbolec2

The problem being with people who spend thousands, if not hundreds of thousands of dollars on ineffective treatments after being conned into believing something that won't work.

[brmbolec2]

you'd agree with alternative medicine/placebo in cases "[...] where there is no effective treatement". and i think that's very often the case. people first turn to a classical doctor, and when that doesn't work, they try something else. ie with lower probability of success. quite rational to me.