User Guide

383
GLM Univariate
Analysis

Any regression model.
 A purely nested design. (This form of nesting can be specified by using syntax.)
Type III. The default. This method calculates the sums of squares of an effect in the
design as the
sums of squares adjusted for any other effects that do not contain it and
orthogonal to any effects (if any) that contain it. The Type III sums of squares have
one major advantage in that they are invariant with respect to the cell frequencies
as long as th
e general form of estimability remains constant. Hence, this type of
sums of squares is often considered useful for an unbalanced model with no missing
cells. In a factorial design with no missing cells, this method is equivalent to the
Yates’ wei
ghted-squares-of-means technique. The Type III sum-of-squares method
is commonly used for:
 AnymodelslistedinTypeIandTypeII.
 Any balanced or unbalanced model with no empty cells.
Type IV. This method is designed for a situation in which there are missing cells. For
any effect
F in the design, if F is not contained in any other effect, then Type IV =
Type III = Type II. When F is contained in other effects, Type IV distributes the
contrasts being made among the parameters in F to all higher-level effects equitably.
The Type I
V sum-of-squares method is commonly used for:
 Any mode
ls listed in Type I and Type II.
 Any bala
nced model or unbalanced model with empty cells.
GLM Contrasts
Figure 22-4
Univariate Contrasts dialog box