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Re: st: Interpretation of Two-sample t test with equal variances?


From   "JVerkuilen (Gmail)" <jvverkuilen@gmail.com>
To   statalist@hsphsun2.harvard.edu
Subject   Re: st: Interpretation of Two-sample t test with equal variances?
Date   Wed, 20 Mar 2013 14:53:43 -0400

On Wed, Mar 20, 2013 at 10:33 AM, Nick Cox <njcoxstata@gmail.com> wrote:

> However, it is also likely that the means are hiding important details
> in the distributions. <...>
>
> Although I have much faith that Student's t test works well even if
> you lie to it, skewness sounds like an area for investigation.

Agreed. Mean differences may not be all that important.



My gut
> instinct is that turning the problem round to make it a logit
> regression on age makes much more sense. I would use a fractional
> polynomial or cubic spline in age and always plot some smooth summary
> of one or other fraction (e.g. fraction C or fraction V) versus age.

Continuing in my spirit of "me, too!"... very good advice.
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