User Guide

8
Chapter 1
GLM Multivariate Profile Plots
Figure 1-4
Multivariate Profile Plots dialog box
Profile plots (interaction plots) are useful for comparing marginal means in your
model. Profile plots are created for each dependent variable. A profile plot is a line plot
in which each point indicates the estimated marginal mean of a dependent variable
(adjusted for covariates) at one level of a factor. The levels of a second factor can be
used to make separate lines. Each level in a third factor can be used to create a separate
plot. All fixed factors are available for plots.
A profile plot of one factor shows whether the estimated marginal means are
increasing or decreasing across levels. For two or more factors, parallel lines indicate
that there is no interaction between factors, which means that you can investigate the
levels of only one factor. Lines that cross each other indicate an interaction.
Figure 1-5
Nonparallel plot (left) and parallel plot (right)