Dear all,
I have to check for correlation among variables. The data come from a
within - subject experiment. This is an example to illustrate how my data
are organized (I have 40 groups at the moment - distributed over 3
treatments):
id group x1 x2 x3
1 1 15 15 20
2 1 15 20 20
3 1 18 18 18
4 1 15 15 15
5 2 20 20 20
6 2 18 18 18
7 2 18 18 20
8 2 20 20 20
I want to check whether, for each individual (id), x1, x2 and x3 are
correlated.
My question is: is it correct to run a Spearman's correlation test (or a
Pearson's correlation test if I manage to collect more observations) even
if observations within the same group are probably not independent? What
should I do?
Thank you
F.P.
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