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Re: st: Using Kolmogorov-Smirnov test (ksmirnov)


From   Nick Cox <[email protected]>
To   [email protected]
Subject   Re: st: Using Kolmogorov-Smirnov test (ksmirnov)
Date   Thu, 21 Feb 2013 18:03:14 +0000

Quantile-quantile plots show more information and make the question of
adjusting for location and scale the side-issue you want it to be. In
your situation you expect a linear configuration. If you standardise
too,  you expect that to be equality. -qqplot- beckons. If someone in
power over you expects inferential mumbo-jumbo too, then get an idea
of variability from e.g. bootstrapping.

When it's sensitive, K-Smirnov is sensitive to differences in the
middle of distributions. For most practical statistics, you need to
worry more about the tails.

Nick

On Thu, Feb 21, 2013 at 5:36 PM, Zachary Neal <[email protected]> wrote:
> I would like to determine whether two samples have the same
> distribution form, despite having means and variances that are known
> (and expected) to be different.  Before performing a
> Kolmogorov-Smirnov test, is it necessary to transform the two samples
> so they have a common mean? A common variance?  I'm inclined to use
> z-scores so that any difference detected by ksmirnov is attributable
> to a difference in form, and not to a difference in mean or variance,
> but I'm not sure this is right.
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