Effect sizes from 3 or more means

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Effect sizes from 3 or more means

Postby gww » Tue Dec 09, 2008 1:06 pm

Hi, can anybody tell me how to calculate cohen's d from ANOVAs using 3 means?
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Postby statman » Tue Dec 09, 2008 1:43 pm

ES (Cohen's d) is the acceptable "risk" between the null & alternative hypotheses so, as I am aware, by definition it is always between to outcomes. If you have 3 then there would be an ES between the null and each of the 2 other alternatives.

However, the estimated effect size for an ANOVA is the Eta Squared.
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