Pierce, Charles A., Block, R. A., and Aguinis, Herman
Educational and Psychological Measurement Vol. 64 Issue 6, p. 916-924.

We provide a cautionary note on reporting accurate eta-squared values from multifactor analysis of variance (ANOVA) designs. We reinforce the distinction between classical and partial eta squared as measures of strength of association. We provide examples from articles published in premier psychology journals in which the authors erroneously reported partial eta-squared values as representing classical eta-squared values. Finally, we discuss broader impacts of inaccurately reported eta-squared values for theory development, meta-analytic reviews, and intervention programs.