Mplus Users Guide v6.. - Muthén & Muthén

CHAPTER 9TITLE:this is an example of a two-levelregression analysis for a continuousdependent variable with a random interceptand an observed covariateThe TITLE command is used to provide a title for the analysis. The titleis printed in the output just before the Summary of Analysis.DATA:FILE = ex9.1a.dat;The DATA command is used to provide information about the data setto be analyzed. The FILE option is used to specify the name of the filethat contains the data to be analyzed, ex9.1a.dat. Because the data set isin free format, the default, a FORMAT statement is not required.VARIABLE:NAMES = y x w xm clus;WITHIN = x;BETWEEN = w xm;CLUSTER = clus;CENTERING = GRANDMEAN (x);The VARIABLE command is used to provide information about thevariables in the data set to be analyzed. The NAMES option is used toassign names to the variables in the data set. The data set in thisexample contains five variables: y, x, w, xm, and clus.The WITHIN option is used to identify the variables in the data set thatare measured on the individual level and modeled only on the withinlevel. They are specified to have no variance in the between part of themodel. The BETWEEN option is used to identify the variables in thedata set that are measured on the cluster level and modeled only on thebetween level. Variables not mentioned on the WITHIN or theBETWEEN statements are measured on the individual level and can bemodeled on both the within and between levels. Because y is notmentioned on the WITHIN statement, it is modeled on both the withinand between levels. On the between level, it is a random intercept. TheCLUSTER option is used to identify the variable that contains clusteringinformation. The CENTERING option is used to specify the type ofcentering to be used in an analysis and the variables that are to becentered. In this example, grand-mean centering is chosen.240