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Re: st: Cramers V with weighted data


From   Steven Samuels <sjhsamuels@earthlink.net>
To   statalist@hsphsun2.harvard.edu
Subject   Re: st: Cramers V with weighted data
Date   Thu, 14 Aug 2008 12:55:50 -0400

I have to apologize to everyone. The statistic computed by the formula that I gave is Cramer's Phi statistic, which is Cramer's V for 2x2 tables. Thanks to Nick Cox for pointing out my error and pointing me to the proper definition.

The proper formula for Cramer's V is:


di "Cramer's V = " sqrt(e(cun_Pear)/(e(N)*min((e(r)-1),(e(c)-1))))

-Steve
On Aug 14, 2008, at 10:47 AM, Waldo, Daniel R. (CMS/ORDI) wrote:


In the case of complex survey design, should the denominator of the
calculation take the design effect into consideration? That is, should I
use N/DEff as opposed to N?
------------------------------

Date: Tue, 12 Aug 2008 08:34:30 -0400
From: Steven Samuels <sjhsamuels@earthlink.net>
Subject: Re: st: Cramers V with weighted data

I did.

Thanks, Paul.

- -Steve
On Aug 12, 2008, at 5:21 AM, Paul Seed wrote:


I think Steven meant:

	gen crV= sqrt(e(cun_Pear)/e(N))

or:

	di "Cramer's V = " sqrt(e(cun_Pear)/e(N))


Paul Seed, Lecturer in Medical Statistics
KCL School of Medicine, Division of Reproduction and Endocrinology
tel  (+44) (0) 20 7188 3642

On Aug 8, 2008, at 12:21 PM, Steven Samuels wrote:
.
-svyset- the data with pweights equal to your weight. Run -svy:
tabulate- and divide the uncorrected Pearson Chi Square statistic
by the sample size.  You can program this by dividing the returned
scalar e(cun_Pear) by the scalar e(N)

gen crV= e(cun_Pear)/e(N)

-Steve

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