Using an EXCEL spreadsheet to compute generalized omega^2^
This spreadsheet computes generalized omega2 as recommended by Olejnik and Algina (2003). It will work out generalized omega2 for any term in a mixed ANOVA with upto three factors (any combination of between and within subject factors).
You need to firstly enter the number of factors (between and within) in the ANOVA and the term for which you requite the effect size. When you have done this enter sums of squares and their degrees of freedom in column B for terms appearing in column A. You also need to add in the total number of observations in cell B42 and a Y or N to denote whether each factor in the ANOVA is either manipulated (non-random) or measured (random).