29 Nov
2012
29 Nov
'12
2:58 p.m.
Hi - thanks - I was thinking about doing it the other way (3 separate groups) because as well as looking to see whether there is a linear change in dependent measures (eg area) across groups I also want to see if there is a linear change in the slope of dependent measure against age across the 3 groups. I can' t see how to do that with the single group method against 1,2,3 covariates.
Is there a way of doing it ?
Also why do you recommend the 1 group method ? Better powered
Thanks.
Mahinda