I have a question about how to use Mplus to define longitudinal patterns of multivariate psychological variables.
We have three observation time points (j=1,2,3). In j-th observation time we observe distress score (Y_j1), somatization score (Y_j2), and anxiety score (Y_j3). If at each observation time we use a global score (Y_j) for the three variables, it is easy to write the code as following, suppose we want 4 classes. Usevariables are Y_1 Y_2 Y_3; Classes=c(4);
But the investigator insists to use three variables at each time point to classify 4 longitudinal patterns (not three independent models for distress, somatization, anxiety, separately). Then can I write as the following? Usevariables are Y_11 Y_12 Y_13 Y_21 Y_22 Y_23 Y_31 Y_32 Y_33; Classes=c(4);
If it is wrong to write in this way, what should I do? Do you have any similar example for me to refer? Thank you very much for your answer!
You can write it the way you propose. Your model becomes a parallel process model (although with 3 instead of 2 processes). See the UG index for such a model. To which it sounds like you want to add one latent class variable that is determined by all 3 processes.