Mplus Users Guide v6.. - Muthén & Muthén

CHAPTER 14covariances and regression coefficients. Multiple group analysis is notavailable for TYPE=MIXTURE and EFA. Multiple group analysis forTYPE=MIXTURE can be carried out using the KNOWNCLASS optionof the VARIABLE command. Following are the topics discussed in thissection:• Requesting a multiple group analysis• First group in multiple group analysis• Defaults for multiple group analysis• MODEL command in multiple group analysis• Equalities in multiple group analysis• Means/intercepts/thresholds in multiple group analysis• Scale factors in multiple group analysis• Residual variances of latent response variables in multiple groupanalysis• Data in multiple group analysis• Testing for measurement invariance using multiple group analysisREQUESTING A MULTIPLE GROUP ANALYSISThe way to request a multiple group analysis depends on the type of datathat are being analyzed. When individual data stored in one data set areanalyzed, a multiple group analysis is requested by using theGROUPING option of the VARIABLE command. When individual datastored in different data sets are analyzed, multiple group analysis isrequested by using multiple FILE statements in the DATA command.When summary data are analyzed, multiple group analysis is requestedby using the NGROUPS option of the DATA command.FIRST GROUP IN MULTIPLE GROUP ANALYSISIn some situations it is necessary to know which group the programconsiders to be the first group. How the first group is defined differsdepending on the type of data being analyzed. For individual data in asingle data set, the first group is defined as the group with the lowestvalue on the grouping variable. For example if the grouping variable isgender with males having the value of 1 and females having the value of0, then the first group is females. For individual data in separate datasets, the first group is the group represented by the first FILE statement422