[R] squared semi-partial correlation

[N.Callow]

Hi, can you help? I am really struggling to find the answer to the
following question.

I have conducted a standard multiple regression using SPSS. The dependent
variable is CE, and the independent variables are Ibelieve and Tbelieve.
Because the independent variables are highly correlated I have examined the
squared semi-partial correlations. I
understand that the Ibelieve squared semi partial correlation accounts for
a significant proportion of the variance in CE t= 2.689, whereas the
tbelieve does not t = .556. However, I want to see if the squared
semi-partial correlations are significantly different TO EACH OTHER
(Ibelieve .168, Tbelieve .035 N= 220). How do I do this?  I assume that I
will need to do this "by hand" with an equation? Also, do I have to take
into account that the squared semi-partial correlations are correlated in
terms of the dependent variable? 
Thanks very much.
Nichola


-- 
http://www.shes.bangor.ac.uk/home.html
------------ 
Dr Nichola Callow (C.Psychol.)
School of Sport, Health, and Exercise Science
University of Wales, Bangor
George Building
Holyhead Road
Bangor
Gwynedd LL57 2PX
Tel: 44 (0) 1248 388243
Fax: 44 (0) 1248 371053
E-Mail: n.callow at bangor.ac.uk