[tips] RE: Nonparametric Effect Size and Post-Hoc Power

[Marc Carter]

Seconded.   I'd be interested in hearing about this, too.  It seems to me that the computation of power has to make assumptions about the shape of the distribution of the dependent variable (power is essentially a measure of area of the distribution of the variable -- under the alternative hypothesis -- above the criterion), and so if we cannot make assumptions about the character of that distribution (that's why they're called "distribution-free stats"), I'm at a loss to figure how we'd compute its area.    I'm wondering if there's some way to bootstrap a distribution based on the data, generate a function to describe it, and then get about integrating it.   But, as often happens, I could be wrong and would really like to know.   m ------- "Mauchly's Test of Sphericity: Tests the null hypothesis that the error covariance matrix of the orthonormalized transformed dependent variables is proportional to an identity matrix." --- SPSS   From: ROBERT [EMAIL PROTECTED]@MATHSCIENCE [mailto:[EMAIL PROTECTED] Sent: Thursday, September 28, 2006 6:47 AM To: Teaching in the Psychological Sciences (TIPS) Subject: [tips] Nonparametric Effect Size and Post-Hoc Power Anyone out there familiar with way to calculate effect size and post-hoc power following nonparametric analyses (specifically Kruskal-Wallis ANOVAs and Mann-Whitney U tests)?   Thanks,   Rob Flint -------------------------------------------------------------------- Robert W. Flint, Jr., Ph.D. Associate Professor of Psychology The College of Saint Rose 432 Western Avenue Albany, NY  12203-1490   [EMAIL PROTECTED] 518.458.5379   Behavioral/Cognitive Neuroscience Web Page - http://academic2.strose.edu/Math_And_Science/flintr/   Journal of Behavioral and Neuroscience Research - http://academic2.strose.edu/Math_And_Science/flintr/jbnr/   --- To make changes to your subscription go to: http://acsun.frostburg.edu/cgi-bin/lyris.pl?enter=tips&text_mode=0&lang=english --- To make changes to your subscription go to: http://acsun.frostburg.edu/cgi-bin/lyris.pl?enter=tips&text_mode=0&lang=english