Which analysis to choose? Urgent

[TruroJP]

Hi, any help is greatly appreciated.

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!

 

[hlsmith]

Numbers 1-4? Integers or any value. What do these values look like when you plot them?

 

[TruroJP]

Hi - they are not integers, 2.344 is one of the points for example. So the data is continuous. Since there is just one mean value for each group I cant plot them - or do you mean if I were to plot every case's mean score from the questionnaire?

 

[TruroJP]

From what ive found, an independent samples t-test or a one way ancova might work (considering gender might be a covariate) - sorry I'm very bad with stats. Thanks for any help.

 

[hlsmith]

What is your sample size and do you have any missing data?

 

[TruroJP]

About 8000, and no missing data - but ive basically just been given the variables in stata. I basically just need to compare the two groups on the variable, though ive been told a longitudinal approach i.e. comparing trajectories would be a lot stronger.