I have data from the same children at ages 4, 7 and 11 for a variable (self-regulation) created from a questionnaire. The data for this variable is numbers from 1-4 (the mean of their scores from the questionnaire).

I need to compare the differences between two populations on this variable. So, my populations are 1) Those with learning disorders 2) Everyone else.

So basically what I need to do is compare the mean self-regulation scores at age 4 between two populations, then at age 7 and again at age 11 - what analysis would be required to do this?

OR - I can compare the trajectories of self-regulation between the two groups i.e. look at it longitudinally - would an anova be appropriate here for comparing the trajectories?

Again any help will help me out a lot - Also I am using stata.

Thanks!