Mplus Users Guide v6.. - Muthén & Muthén

TITLE, DATA, VARIABLE, And DEFINE CommandsIn most situations, the default recoding is appropriate. In multiple groupanalysis and growth modeling, the default recoding may not beappropriate because the categories observed in the data for a variablemay not be the same across groups or time. For example, it is sometimesthe case that individuals are observed in lower categories at earlier timepoints and higher categories at later time points. Several variations ofthe CATEGORICAL option are available for these situations. These areallowed only for maximum likelihood estimation.Using the automatic recoding, each variable is recoded using thecategories found in the data for that variable. Following is an exampleof how to specify the CATEGORICAL option so that each variable isrecoded using the categories found in the data for a set of variables:CATEGORICAL u1-u3 (*);where u1, u2, and u3 are a set of ordered categorical variables and theasterisk (*) in parentheses indicates that the categories of each variableare to be recoded using the categories found in the data for the set ofvariables not for each variable. Based on the original data shown in thetable below, where the rows represent observations and the columnsrepresent variables, the set of variables are found to have four possiblecategories: 1, 2, 3, and 4. The variable u1 has observed categories 1and 2; u2 has observed categories 1, 2, and 3; and u3 has observedcategories 2, 3, and 4. The recoded values are shown in the table below.Categories in the Original Data SetCategories in the Recoded Data Setu1 u2 u3 u1 u2 u31 2 3 0 1 21 1 2 0 0 12 2 2 1 1 12 3 4 1 2 3The CATEGORICAL option can be used to give a set of categories thatare allowed for a variable or set of variables rather than having thesecategories determined from the data. Following is an example of how tospecify this:CATEGORICAL = u1-u3 (1-6);489