o Spread-versus-level plots depict standard deviations vs. means, or variances vs. means, for each dependent variable. Each point shows the value of a factor design matrix group cell on the mean and on the standard deviation or variance. This is useful in testing the homogeneity of variances assumption, and in identifying cells which deviate substantially from the assumption.
o Observed*Predicted*Standardized Residual Plots. For each dependent variable, a plot is produced which shows the 6 comparisons among observed, predicted, and standardized residuals. For observed by predicted, one would like to see a clear pattern, but for the plots involving standardized residuals, one would like not to see a pattern.
o Profile plots are line plots of the predicted means of each dependent variable across levels of each factor. When two or three factors are involved, these are called interaction plots. Where a plot of observed means would show the effect being studied and the error, the profile plots of predicted means show the effect without the error. Each point in a profile plot indicates the estimated marginal mean of the dependent variable (adjusted for covariates in MANCOVA) at one level of a given factor. The profile plot shows if the estimated marginal means are increasing across levels. A second or third factor can be represented by a second or third line (not shown below), where parallel lines indicate no interaction and crossing lines indicate interaction among the factors.