Mplus Users Guide v6.. - Muthén & Muthén

CHAPTER 15Fractional values can be used to provide information about theprobability of class membership when class membership is not estimatedbut is fixed at fractional values for each individual. For example, anindividual who has a probability of .9 for being in class 1, .05 for beingin class 2, and .05 for being in class 3 would have t1=.9, t2=.05, andt3=.05. Fractional training data must sum to one for each individual.Following is an example of how the TRAINING option is used for anexample with three latent classes where the training variables containinformation about probabilities of class membership:TRAINING = t1 t2 t3 (PROBABILITIES);where t1, t2, and t3 are variables that contain information about theprobability of latent class membership. The variable t1 providesinformation about the probability of membership in class 1, t2 providesinformation about the probability of membership in class 2, and t3provides information about the probability of membership in class 3.Priors can be used when individual class membership is not known butwhen information is available on the probability of an individual beingin a certain class. For example, an individual who has a probability of .9for being in class 1, .05 for being in class 2, and .05 for being in class 3would have t1=.9, t2=.05, and t3=.05. Prior values must sum to one foreach individual.Following is an example of how the PRIORS option is used for anexample with three latent classes where the training variables containinformation about priors of class membership:TRAINING = t1 t2 t3 (PRIORS);where t1, t2, and t3 are variables that contain information about theprobability of being in a certain class. The variable t1 providesinformation about the probability of membership in class 1, t2 providesinformation about the probability of membership in class 2, and t3provides information about the probability of membership in class 3.508