Mplus Users Guide v6.. - Muthén & Muthén

CHAPTER 8All longitudinal mixture models can be estimated using the followingspecial features:• Single or multiple group analysis• Missing data• Complex survey data• Latent variable interactions and non-linear factor analysis usingmaximum likelihood• Random slopes• Individually-varying times of observations• Linear and non-linear parameter constraints• Indirect effects including specific paths• Maximum likelihood estimation for all outcome types• Bootstrap standard errors and confidence intervals• Wald chi-square test of parameter equalities• Test of equality of means across latent classes using posteriorprobability-based multiple imputationsFor TYPE=MIXTURE, multiple group analysis is specified by using theKNOWNCLASS option of the VARIABLE command. The default is toestimate the model under missing data theory using all available data.The LISTWISE option of the DATA command can be used to delete allobservations from the analysis that have missing values on one or moreof the analysis variables. Corrections to the standard errors and chisquaretest of model fit that take into account stratification, nonindependenceof observations, and unequal probability of selection areobtained by using the TYPE=COMPLEX option of the ANALYSIScommand in conjunction with the STRATIFICATION, CLUSTER, andWEIGHT options of the VARIABLE command. TheSUBPOPULATION option is used to select observations for an analysiswhen a subpopulation (domain) is analyzed. Latent variable interactionsare specified by using the | symbol of the MODEL command inconjunction with the XWITH option of the MODEL command. Randomslopes are specified by using the | symbol of the MODEL command inconjunction with the ON option of the MODEL command. Individuallyvaryingtimes of observations are specified by using the | symbol of theMODEL command in conjunction with the AT option of the MODELcommand and the TSCORES option of the VARIABLE command.Linear and non-linear parameter constraints are specified by using theMODEL CONSTRAINT command. Indirect effects are specified byusing the MODEL INDIRECT command. Maximum likelihood198