# RE: RE: Re: st: RE: kolmogorov-Smirmov Output

 From Garry Anderson To statalist@hsphsun2.harvard.edu Subject RE: RE: Re: st: RE: kolmogorov-Smirmov Output Date Wed, 14 Jan 2009 20:51:57 +1100

```Hi Claudia,
You only need to consider the exact p-value.
Your conclusion that the two distributions are not equal to each other is consistent with the p-value.

Garry

________________________________

From: owner-statalist@hsphsun2.harvard.edu on behalf of ag86264@studbocconi.it
Sent: Wed 14/01/09 20:42
To: statalist@hsphsun2.harvard.edu
Subject: RE: Re: st: RE: kolmogorov-Smirmov Output

Thanks...
So, are my conclusions exact? I do not know if I have to consider the
first and the second p-values too..

Why not use the exact p-value, as reported by

ksmirnov x, by(group) exact

Regards, Garry

________________________________

From: owner-statalist@hsphsun2.harvard.edu on behalf of ag86264@studbocconi.it
Sent: Wed 14/01/09 20:17
To: statalist@hsphsun2.harvard.edu
Subject: Re: st: RE: kolmogorov-Smirmov Output

thanks a lot.
So, if my output is, for example,

Two-sample Kolmogorov-Smirnov test for equality of distribution functions:

Smaller group       D       P-value  Corrected
----------------------------------------------
male:               0.2468    0.002
female:             0.0000    1.000
Combined K-S:       0.2468    0.005      0.003

if a should drow a conlusion, I have to see the p-value 0.005, the row
Combined K-S, is it right? So, in this case, if my alpha is 0.05,
because p-value is less than 0.05 I reject the null hypotesis.Is it
right?

Claudia

Quoting hind sbihi <sbihi@interchange.ubc.ca>:

> Claudia
>
> I am not sure I fully understand your question.
> However, for hypothesis testing, you need to set a critical value at which
> you accept or reject the null hypothesis. Let's say this critical value, or
> alpha is 0.05. Now, if p-value is less than 0.05 your reject the null
> hypothesis (which states that your observed distribution follows a Gaussian
> distribution). Conversely, if p>0.05 then you accept the null hypothesis and
> consider that your data approximates a Gaussian distribution.
> HTH
>
> Hind
>
> -----Original Message-----
> From: owner-statalist@hsphsun2.harvard.edu
> [mailto:owner-statalist@hsphsun2.harvard.edu] On Behalf Of
> ag86264@studbocconi.it
> Sent: Wednesday, January 14, 2009 12:07 AM
> To: statalist@hsphsun2.harvard.edu
> Subject: st: kolmogorov-Smirmov Output
>
>
> Hello,
>
> would someone guide me on how to interpret the output of a two-sided
> kolmogorov-Smirnov test?
> In order to conclude for the equality or not of the distributions, what
> p-value I have to see? As you know, if I perform a test for the
> equality of two distributions, I have three rows where the last one is
> the combined K-S. My question is if I have to see only this last row
> (p-value) in ordwer to drow a conclusion.
>
> thanks a lot
> Claudia
>
>
>
>
>
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