IBM® SPSS® Amos™ 28
Frees or constrains the mean of an exogenous variable.
The Mean method accomplishes the same thing, and is recommended for new Amos programs. The syntax of the MStructure method resembles the syntax of the $MStructure command in previous versions of Amos, and is provided to assist in the translation of old Amos input files.
Syntax
object.MStructure (s)
The MStructure method syntax has the following parts:
Part |
Description |
object |
An object of type AmosEngine. |
s |
A character string in one of the following forms 1.variablename 2.variablename (number) 3.variablename (parametername) 4.variablename (number ?) 5.variablename (parametername : number) In the first form, the mean of the variable named variablename is a free parameter. In the second form, the mean of the variable named variablename is fixed at number. In the third form, the mean of the variable named variablename is given the name parametername. In the fourth form, the mean of the variable named variablename is a free parameter, and is given an initial value of number. In the fifth form, the mean of the variable named variablename is given the name parametername and an initial value of number. |
Placement: [2].
Default
When the ModelMeansAndIntercepts method is not used, then all means and intercepts are unconstrained. However, no means or intercepts are estimated.
When the ModelMeansAndIntercepts method is used, the following default assumptions are made about exogenous variables that are not constrained or fixed at constant values by use of the MStructure or Mean methods.
The means of observed, exogenous variables are free parameters.
The means of unobserved, exogenous variables are fixed at zero.
Remarks
The ModelMeansAndIntercepts method must be used before using the MStructure method.
It is possible to name an endogenous variable as an argument to the MStructure method. Doing so has the effect of freeing or constraining the intercept in the regression equation for predicting that variable. However, the following methods for specifying constraints on intercepts are recommended.
▪Include the intercept in a linear equation through use of the AStructure method.
▪Use the Intercept method.
See Also
