SPSS® 12.0 Command Syntax Reference

646 GLM: Overview
Models
• Estimated marginal means (EMMEANS) and standard errors adjusted for other factors and
covariates are available for all between- and within-subjects factor combinations in the
original variable metrics.
• Uncorrected pairwise comparisons among estimated marginal means for any main effect
in the model, for both between- and within-subjects factors.
• Post hoc or multiple comparison tests for unadjusted one-way factor means are available
for between-subjects factors in ANOVA designs; 20 different types of comparisons are
offered.
• Weighted least squares (WLS) estimation, including saving of weighted predicted values
and residuals.
• Automatic handling of random effects in random-effects models and mixed models, including
generation of expected mean squares and automatic assignment of proper error terms.
• Specification of several types of nested models via dialog boxes with proper use of the
interaction operator (*), due to the nonreparameterized approach.
• Univariate homogeneity-of-variance assumption tested using the Levene test.
• Between-subjects factors do not require specification of levels.
• Profile (interaction) plots of estimated marginal means for visual exploration of interactions
involving combinations of between- and/or within-subjects factors.
• Saving of casewise temporary variables for model diagnosis:
• Predicted values—unstandardized (raw), weighted unstandardized.
• Residuals—unstandardized, weighted unstandardized, standardized, Studentized, deleted.
• Standard error of prediction.
• Cook’s distance.
• Leverage.
• Saving of an SPSS file with parameter estimates and their degrees of freedom, significance
level.
To simplify the presentation, reference material on GLM is divided into three sections:
univariate designs with one dependent variable, multivariate designs with several
interrelated dependent variables, and repeated measures designs, in which the dependent
variables represent the same types of measurements taken at more than one time.
The full syntax diagram for GLM is presented here. The GLM sections that follow include
partial syntax diagrams showing the subcommands and specifications discussed in that
section. Individually, those diagrams are incomplete. Subcommands listed for univariate designs
are available for any analysis, and subcommands listed for multivariate designs can be
used in any multivariate analysis, including repeated measures.
The following are examples of models that can be specified using GLM:
Model 1: Univariate or multivariate simple and multiple regression
GLM Y WITH X1 X2.
GLM Y1 Y2 WITH X1 X2 X3.