The denominator of ω2 in a factorial design is inflated owing to rectangularity of the distribution of the factors in analysis of variance, while many quantitative psychological variables are normally distributed. The magnitude of the bias depends on the correlation between the dependent variable and the relevant factor and is therefore relative to each experiment. Corrections of ω2 for range are discussed.
Get full access to this article
View all access options for this article.
References
1.
FleissJ. L.Estimating the magnitude of experimental effects. Psychological Bulletin, 1969, 72, 273–276.
2.
GlassG. V., & HakstianA. R.Measures of association in comparative experiments: their development and interpretation. American Educational Research Journal, 1969, 6, 403–414.
3.
HaysW. L.Statistics for psychologists.New York: Holt, Rinehart, & Winston, 1963.