Mplus Users Guide v6.. - Muthén & Muthén

Special Modeling Issuesthe grouping variable that is not specified using the GROUPING option,it is not included in the analysis.INDIVIDUAL DATA, DIFFERENT DATA SETSFor individual data stored in different data sets, the specification of theFILE option of the DATA command has two differences for multiplegroup analysis. First, a FILE statement is required for each data set.Second, the FILE option allows a label to be specified that can be usedin the group-specific MODEL commands. In the situation where thedata for males are stored in a file named male.dat, and the data forfemales are stored in a file named female.dat, the FILE option isspecified as follows:FILE (male) = male.dat;FILE (female) = female.dat;The labels male and female can be used in the group-specific MODELcommands to specify differences between the group-specific models formales and females and the overall model.When individual data are stored in different data sets, all of the data setsmust contain the same number of variables. These variables must beassigned the same names and be read using the same format.SUMMARY DATA, ONE DATA SETSummary data must be stored in one data set with the data for the firstgroup followed by the data for the second group, etc.. For example, inan analysis of means and a covariance matrix for two groups with fourobserved variables, the data would appear as follows:0 0 0 021 21 1 21 1 1 21 1 1 1431