User Guide

381
GLM Univariate
Analysis
GLM Model
Figure 22-3
Univariate M odel dialog box
Specify Model. A full factorial model contains all factor main effects, all covariate
main effects, and all factor-by-factor interactions. It does not contain covariate
interactions. Select
Custom to specify only a subset of interactions or to specify
factor-by-covariate interactions. You must indicate all of the terms to be included
in the model.
Factors and Covariates. The factors and covariates are listed with (F) for fixed factor
and (C) for covariate. In a Univariate analysis, (R) indicates a random factor.
Model. The model depends on the nature of your data. After selecting Custom,you
can select the main effects and interactions that are of interest in your analysis.
Sum of squares. The method of calculating the sums of squares. For balanced or
unbalanced models with no missing cells, the Type III sum-of-squares method is
most commonly used.
Include intercept in model. The intercept is usually included in the model. If you can
assume that the data pass through the origin, you can exclude the intercept.