Mplus Users Guide v6.. - Muthén & Muthén

CHAPTER 16values produced by the program. Maximum likelihood optimization isdone in two stages. In the initial stage, random sets of starting values aregenerated. An optimization is carried out for ten iterations using each ofthe random sets of starting values. The ending values from theoptimizations with the two highest loglikelihoods are used as the startingvalues in the final stage optimizations which are carried out using thedefault optimization settings for TYPE=MIXTURE.When TYPE=TWOLEVEL with categorical outcomes and weightedleast squares estimation or TYPE=EFA is used random sets of startingvalues are generated for the factor loading parameters in the model. ForTYPE=TWOLEVEL with categorical outcomes and weighted leastsquares estimation, these random sets of starting values are randomperturbations of either user-specified starting values or default startingvalues produced by the program. For TYPE=EFA, these random sets ofstarting values are random perturbations of default starting valuesproduced by the program.STARTSThe STARTS option is used to specify the number of random sets ofstarting values to generate in the initial stage and the number ofoptimizations to use in the final stage. For TYPE=MIXTURE, thedefault is 10 random sets of starting values in the initial stage and 2optimizations in the final stage. To turn off random starts, the STARTSoption is specified as follows:STARTS = 0;Following is an example of how to use the STARTS option forTYPE=MIXTURE:STARTS = 20 5;specifies that 20 random sets of starting values are generated in theinitial stage and 5 optimizations are carried out in the final stage usingthe default optimization settings for TYPE=MIXTURE.Following are recommendations for a more thorough investigation ofmultiple solutions:550