Greetings Experts,

I use stata version 15.0. I have longitudinal data that I am trying to fit some mixed models. My outcome is distance (facial distance), below shown as dist, and my independent is age. I also have ID and each participant is measured at 4 time points (repeated measures). I would like to confirm with experts here whether my commands, under different conditions, are correct (My main interest is on command #3 fitting random slope only assuming fixed intercept- though not a common scenario):

1. *Random intercept unconditional model
mixed dist || ID:, var ml


2. *Random intercept only
mixed dist age || ID:, var ml


3. *Random slope only
mixed dist age ||age:, var ml

4. *Both Random intercept & random slope
mixed dist age || ID:age, var ml


Your comments will be greatly appreciated.

Owen