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From Kim van der Linde <...@kimvdlinde.com>
Subject Re: [math] API changes for RC2
Date Mon, 27 Sep 2004 01:30:45 GMT


Al Chou wrote:

> -0; question:  do people really use the population version?  When dealing with
> real-world data or any other distribution that is not known a priori, how could
> you, in good conscience?  And if you know the distribution a priori, why would
> you need to compute statistics about it?

It depends if you want to minimise error or bias. We do use it at times, 
just like we do change degrees-of-freedom (in many of our multivariate 
analyses by 4 to be precise due to three modifications that take 1, 1, 
and 2 degrees of freedom) in all kind of tests to correct for previous 
calculations on the same data set. In some studies, the variance is 
calculated relative to a set average, which become biased 
the-other-way-around if you would use sample variances.

Anyway, I reported these examples back because of the real life usage.

Cheers,

Kim

-- 
http://www.kimvdlinde.com

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