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SPSS® 12.0 Command Syntax Reference

SPSS® 12.0 Command Syntax Reference

SPSS® 12.0 Command Syntax Reference

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Basic Specification<br />

GLM: Univariate 653<br />

• The basic specification is a variable list identifying the dependent variable, the factors (if<br />

any), and the covariates (if any).<br />

• By default, GLM uses a model that includes the intercept term, the covariate (if any), and<br />

the full factorial model, which includes all main effects and all possible interactions among<br />

factors. The intercept term is excluded if it is excluded in the model by specifying the<br />

keyword EXCLUDE on the INTERCEPT subcommand. Sums of squares are calculated and<br />

hypothesis tests are performed using type-specific estimable functions. Parameters are<br />

estimated using the normal equation and a generalized inverse of the SSCP matrix.<br />

Subcommand Order<br />

• The variable list must be specified first.<br />

• Subcommands can be used in any order.<br />

<strong>Syntax</strong> Rules<br />

• For many analyses, the GLM variable list and the DESIGN subcommand are the only specifications<br />

needed.<br />

• If you do not enter a DESIGN subcommand, GLM will use a full factorial model, with main<br />

effects of covariates, if any.<br />

• Minimum syntax—at least one dependent variable must be specified, and at least one of<br />

the following must be specified: INTERCEPT, a between-subjects factor, or a covariate.<br />

The design contains the intercept by default.<br />

• If more than one DESIGN subcommand is specified, only the last one is in effect.<br />

• Dependent variables and covariates must be numeric, but factors can be numeric or string<br />

variables.<br />

• If a string variable is specified as a factor, only the first eight characters of each value are<br />

used in distinguishing among values.<br />

• If more than one MISSING subcommand is specified, only the last one is in effect.<br />

• The following words are reserved as keywords or internal commands in the GLM procedure:<br />

Limitations<br />

INTERCEPT, BY, WITH, ALL, OVERALL, WITHIN<br />

Variable names that duplicate these words should be changed before you run GLM.<br />

• Any number of factors can be specified, but if the number of between-subjects factors<br />

plus the number of split variables exceeds 18, the Descriptive Statistics table is not printed<br />

even when you request it.

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