Data Assumption: Sphericity

November 11, 2017

Very brief description The assumption of sphericity refers to the equality of variances of the differences between treatment levels.  In Repeated Measures ANOVA it is a measure of the homogeneity of the variances of the differences between levels so it is quite similar to homogeneity of variance in between-groups in the univariate ANOVA. It is denoted by ε and sometimes referred to as “circularity”.   Who cares Sphericity applies to repeated measures ANOVA and MANOVA. While technically not an assumption of Factor Analysis, “Bartlett’s test of [READ MORE]