The MODELEFFECTS statement lists the effects in the data set to be analyzed. Each effect is a variable or a combination of variables, and is specified with a special notation that uses variable names and operators.
Each variable is either a classification (or CLASS) variable or a continuous variable. If a variable is not declared in the CLASS statement, it is assumed to be continuous. Crossing and nesting operators can be used in an effect to create crossed and nested effects.
One general form of an effect involving several variables is
X1 * X2 * A * B * C ( D E )
where A
, B
, C
, D
, and E
are classification variables and X1
and X2
are continuous variables.
When the input DATA= data set is not a specially structured SAS data set, you must also specify standard errors of the parameter estimates in an STDERR statement.