After you perform an ANOVA using **proc glm**, it
is useful to be able to report omega or eta squared as a measure of the strength of the
effect of the independent variable. **Proc glm** does have an “**effectsize**” option
that computes this. Here is an example that shows how to compute
ω^{2} and η^{2}, as well as partial and semi-partial versions.

proc glm data = in.hsb2; class race ses; model write = race ses/ss3 effectsize; run; quit;