# st: RE: can I compare correlations with t-tests (Bonferroni)?

 From "Lachenbruch, Peter" To Subject st: RE: can I compare correlations with t-tests (Bonferroni)? Date Mon, 16 Jun 2008 08:56:35 -0700

```Tests of correlations are notoriously sensitive to the normality
assumption.  So any solutions may be subject to that problem.  One
approach might be to use the Fisher z transformation for the
correlations and then test to see if each is 0 or not.  I'd be cautious

To compare correlation A1 with A10 you would use z(A1)-z(A10) and go
from there.

Tony

Peter A. Lachenbruch
Department of Public Health
Oregon State University
Corvallis, OR 97330
Phone: 541-737-3832
FAX: 541-737-4001

-----Original Message-----
From: owner-statalist@hsphsun2.harvard.edu
[mailto:owner-statalist@hsphsun2.harvard.edu] On Behalf Of
nicola.baldini2@unibo.it
Sent: Monday, June 16, 2008 1:37 AM
To: statalist@hsphsun2.harvard.edu
Subject: st: can I compare correlations with t-tests (Bonferroni)?

I have item A in a scale "interest in participating to their countrys or
to their regions economic and technological development", which I want
to compare with 12 items in another scale.
I would like to show that:
- item A is correlated with 10th, 11th and 12th item in the other scale
- such correlation is "stronger" than between A and 1st item, A and 2nd,
.... A and 9th
This is obvious on the correlation table since correlation between A and
other items are:
0.1095 (A and 1st) 0.1227 (A and 2nd) 0.1285 0.1833 0.1487 0.1546 0.1483
0.2489 0.278 0.2037 (A and 12th)
Is there a way/a test in Stata to say it statistically (i.e. with some
p-value)?
Nicola

P.S. From statalist-digest V4 #3088 on, I noticed that the characters'
size has been reduced (from medium to small, according to Eudora's
version 7 standards). Is it true or did I incidentally changed some
setting on my pc?

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```