User Guide

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Chapter 4
Linear Mixed Models Fixed Effects
Figure 4-3
Linear Mixed Models: Fixed Effects dialog box
Fixed Effects. There is no default model, so you must explicitly specify the fixed effects.
Alternatively, you can build nested or non-nested terms.
Include Intercept. The intercept is usually included in the model. If you can assume the
data pass through the origin, you can exclude the intercept.
Sum of squares. The method of calculating the sums of squares. For models with no
missing cells, the Type III method is most commonly used.
Build Non-Nested Terms
For the selected factors and covariates:
Factorial. Creates all possible interactions and main effects of the selected variables.
This is the default.
Interaction. Creates the highest-level interaction term of all selected variables.
Main Effects. Creates a main-effects term for each variable selected.