z test comparison between two correlations

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z test comparison between two correlations

Karen Wood
Hi all, I have accessed this list to find out how to compare
correlations between correlations and was able to access this
information from back in 2006 -thanks Marta Garcia-Granero!!
As this is part of my doctoral research how exactly to I reference
this procedure? Can it be found in a text, if so which one?

MATRIX.
* Input manually the values for r1, n1, r2, n2 *.
COMPUTE r1=0.8.
COMPUTE n1=20.
COMPUTE r2=-0.5.
COMPUTE n2=30.
PRINT {r1,r2}
  /FORMAT="f8.2"
  /TITLE='Correlation coefficients:'.
PRINT {n1,n2}
  /FORMAT="f8.0"
  /TITLE='Sample sizes:'.
COMPUTE zr1=.5*(LN((1+r1)/(1-r1))).
COMPUTE varzr1=1/(n1-3).
COMPUTE zr2=.5*(LN((1+r2)/(1-r2))).
COMPUTE varzr2=1/(n2-3).
COMPUTE fisherz=(zr1-zr2)/SQRT(varzr1+varzr2).
COMPUTE zsig=2*(1-CDFNORM(ABS(fisherz))).
PRINT {fisherz,zsig}
  /FORMAT="f8.4"
  /CLABELS="Z" "Sig."
  /TITLE='Statistic & significance (two-tailed):'.
END MATRIX.

Thank You

Karen
I

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Re: z test comparison between two correlations

Marta Garcia-Granero
Karen Wood wrote:
> Hi all, I have accessed this list to find out how to compare
> correlations between correlations and was able to access this
> information from back in 2006 -thanks Marta Garcia-Granero!!
> As this is part of my doctoral research how exactly to I reference
> this procedure? Can it be found in a text, if so which one?
Basic & Clinical Biostatistics, Beth Dawson, Robert G. Trapp
McGraw-Hill Professional, 2004
ISBN 0071410171, 9780071410175
Chapter 8,  pp 196

Best regards,
Marta GarcĂ­a-Granero

>
> MATRIX.
> * Input manually the values for r1, n1, r2, n2 *.
> COMPUTE r1=0.8.
> COMPUTE n1=20.
> COMPUTE r2=-0.5.
> COMPUTE n2=30.
> PRINT {r1,r2}
>  /FORMAT="f8.2"
>  /TITLE='Correlation coefficients:'.
> PRINT {n1,n2}
>  /FORMAT="f8.0"
>  /TITLE='Sample sizes:'.
> COMPUTE zr1=.5*(LN((1+r1)/(1-r1))).
> COMPUTE varzr1=1/(n1-3).
> COMPUTE zr2=.5*(LN((1+r2)/(1-r2))).
> COMPUTE varzr2=1/(n2-3).
> COMPUTE fisherz=(zr1-zr2)/SQRT(varzr1+varzr2).
> COMPUTE zsig=2*(1-CDFNORM(ABS(fisherz))).
> PRINT {fisherz,zsig}
>  /FORMAT="f8.4"
>  /CLABELS="Z" "Sig."
>  /TITLE='Statistic & significance (two-tailed):'.
> END MATRIX.
>
> Thank You
>
> Karen
> I
>
> =====================
> To manage your subscription to SPSSX-L, send a message to
> [hidden email] (not to SPSSX-L), with no body text except the
> command. To leave the list, send the command
> SIGNOFF SPSSX-L
> For a list of commands to manage subscriptions, send the command
> INFO REFCARD
>


--
For miscellaneous statistical stuff, visit:
http://gjyp.nl/marta/

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