Re: N versus N-1 [Was: Another Standard Deviation question]

[John W. Kulig]

 

Claudia Stanny wrote:

 
I will also confirm John Kulig's comment that while the variance (computed
using N-1) is an unbiased estimator of the population variance, the square
root of the variance (SD computed using N-1) is _not_ and unbiased
estimator of the population SD.  I've forgotten the mathematical
particulars for why that happens.  As somebody probably said:  "The proof
is out there."  (Sorry, couldn't resist.)
 

    Credit on this point goes to Karl Wuensch (I am still digesting his post on the topic ..)
 

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John W. Kulig                        [EMAIL PROTECTED]
Department of Psychology             http://oz.plymouth.edu/~kulig
Plymouth State College               tel: (603) 535-2468
Plymouth NH USA 03264                fax: (603) 535-2412
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