Significance testing: a picture (well, cartoon) is worth 1000 words.

kevin's picture
Submitted by kevin on Wed, 04/06/2011 - 09:35

Statistical significance testing is a pretty tricky concept. We're planning to post an article on it soon, but until we get round to it, here's a link to something excellent on the topic from the xkcd Web comic. They're illustrating exactly what people misunderstand. Maybe we needn't bother with the article after all...

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significance
xkcd
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Anonymous's picture

Anonymous (not verified)

Wed, 04/06/2011 - 10:08

Weren't they lucky that exactly 1 of their 20 colour tests gave a result significant at the 5% level?
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Anonymous (not verified)

Thu, 04/07/2011 - 09:48

Almost everyone I've shown this cartoon to is unable to clearly describe why or what it's showing - as far as it goes it's a in joke for people who understand the misunderstanding....
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Anonymous (not verified)

Thu, 04/07/2011 - 20:47

I love xkcd. What does R say? > dbinom(1,20,0.05) [1] 0.3773536 So it happens about 38% of the time if the null is true.