Utkun Ozdil posted on Thursday, February 03, 2011 - 11:27 am
Hi, My question is about the coding of categorical covariates in the data file of Mplus. In my model I want to test the effect of gender, socioeconomic status, school type on mathematics achievement. Socioeconomic status has 4 scales and school type has 3 scales. Do you suggest dummy coding for these variables? For instance, should I create 3 dummies for SES and 2 dummies for school type,, and then include these dummy variables in the MODEL part or should I leave them as they are in the data file (without creating any dummies)?
I also hesitated in that whether a multigroup analysis would be more appropriate.
Covariates must be binary or continuous. If you do not recode nominal variables to s set of dummy variables, they will be treated as continuous in model estimation. With ordinal variables, you can create a set of dummy variables or treat them as continuous.