I'm sure this has been written up somewhere. Does anyone have a
formula for the confidence interval of the Cohen type effect size
parameter for a two group comparison (i.e. diff. of means/common
s.d.)?
I think there are two sampling distribution issues: that of the
difference of the means, and that of the estimation of the s.d.. I
guess I'd be imposing the usual Gaussian assumptions if modelling
this but, as an amateur, I admit I don't have a clue where to start
but am sure it wouldn't be so horrid I couldn't program it in S+ if
told the formula!
Anyone? (dons his flak jacket & ducks)
TIA!
Chris
Chris Evans <chris@visped.org or chris@psyctc.org>
Consultant Psychiatrist in Psychotherapy,
Rampton Hospital; Associate R&D Director,
Tavistock & Portman NHS Trust;
Hon. SL Institute of Psychiatry
*** My views are my own and not representative
of those institutions ***
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