ABSTRACT
The hypotheses for testing the main effect of factor B similarly test whether the variance among the means for the random effect of independent variable B is equal to zero. The null hypothesis tests whether the variance among the means for the random effect of independent variable A is equal to zero. The story of multiple comparisons for the two-factor random-effects model is the same as that for the one-factor random-effects model. To conduct a one-factor random-effects analysis of variance (ANOVA) analysis, there are only two differences from the one-factor fixed-effects ANOVA. In examining the scatterplots for evidence of independence, the points should fall relatively randomly above and below a horizontal line at zero. Random assignment of individuals to dance instructor helped ensure that the assumption of independence was met. Additionally, a scatterplot of residuals against the levels of the between-subjects factor was reviewed.
