Disclaimer: English Kinda Thing

The sole purpose of the "English Kinda Thing" is to document my attempts to correct my own mistakes in standard English usage and to share the resources I find. In no way do I attempt to teach nobody English through these blurbs--just as I intend not to teach nobody to be a neurotic and psychotic handicap in Ratology Reloaded or Down with Meds! :-)

Wednesday, April 18, 2012

Eta squared for Two-Way Repeated Measures ANOVA (Mixed design)

The rule thumb for eta-squared effect size is .01 for small, .06 for medium and .14 for large according to Cohen (1988)

The calculation of Eta Squared for Mixed design based on SPSS output-- which is sort of different from the general ANOVA models- can be found here.

Essentially:
eta squared for within=(ss within effect)/(ss within total)
eta squared for between=(ss between effect)/(ss between total)

One thing worth mentioning is that-- say you have one between variable called group, you will see on your between-factor output 3 sources: Intercept, Group, Error.  The SS total for between factor= SS Group+SS Error.  Let go of the intercept.