why not get real simple ...
make a scatterplot where the graphing symbol for males is different than
for females ... this should be adequate for see if the patterns are
different by any substantial amount
do the separate correlations to back up the graph
let it go at that ...
here is an old time graph lplot in minitab that can do that ... a much
better graph can be made say with blue for males and red for females ....
but, have a look at this one anyway
guess what letter goes for which gender?
- A
-
200+
- A A 2 A
Weight - A A A A
- A A
- A 2 A 2
160+ A A A A A
- 2 3 4 A 3 2 2 3 A A
- B A 2 A 2 A 2
- B 2 2 A A
- B B 4 B 2 2
120+ B 3 2 B B A B
- B2 B B B B
- B
- B
-
------+---------+---------+---------+---------+---------+Height
62.5 65.0 67.5 70.0 72.5 75.0
At 07:46 AM 7/2/02 -0700, nothanks wrote:
>Hello all,
>
> I have a client who wants to compare the relationship/association
>of two variables (Y1 and Y2) between 2 groups (say Gender).
>They (statistically challenged) have left it to me to decide
>on method (and how to measure association).
>
> Y1 and Y2 are ordinal, but are actually continuous variables
>binned into 0, .5, 1, 2 and 3. So, I'm o.k. with treating them
>as continuous.
>
> Anyways, here's what I'm thinking.
>
>1) Fit a linear model Y1 = Y2 + Gender + Y2*Gender,
> and see if the interaction term is signficant.
>
> I figured the differences in slope would give me a decent comparison
> of the
> differences in association between Y1 and Y2, between the two groups.
> Keep in mind, I'm not wedded to actually comparing the Pearson
> correlation.
> Hence,
>
>2) Use a Fisher's Z' Statistic to compare the Pearson Correlation.
>
>3) Mantel-Haenszel is out 'cuz of sparse data.
>
>
>I've done 1) and 2) and they agree, insofar as the interaction term
>in 1) and the Z' Statistic in 2) are not signficant.
>
>Any opinions?
>I'm not too familiar with Fisher's Z' so don't know what it's quirks are
>(and AFAIK, couldn't find documentation in SAS for it, and very few
>Google hits).
>
>Thanks!
>
>
>
>#################################################
>.
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Dennis Roberts, 208 Cedar Bldg., University Park PA 16802
<Emailto: [EMAIL PROTECTED]>
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AC 8148632401
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