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Re: st: Fischer Exact Test again


From   David Greenberg <dg4@nyu.edu>
To   statalist@hsphsun2.harvard.edu
Subject   Re: st: Fischer Exact Test again
Date   Mon, 10 Jun 2002 22:37:16 -0400

For purposes of calculating Fisher's exact test, that is a huge sample, 
because of all the factorials that need to be computed. With moderately 
sized samples in each cell, the chi-square test approaches so closely to 
the exact test that there is little reason to do the exact test. David 
Greenberg, Sociology Department, New York University, New York, NY 
10003.

----- Original Message -----
From: "JiTian Sheu" <jtsheu@bu.edu>
Date: Monday, June 10, 2002 10:29 pm
Subject: st: Fischer Exact Test again

> Dear listers:
> I sent this subject yesterday(or the day before yesterday), and 
> got the
> reply from Mr. Nick.
> I do appreciate your assistence on this subject.
> And I did try to use Auto dataset and see whether for a 2XC(C>2) 
> table, I
> can obtain Fischer exact p-value or not.
> And It does work.
> 
> However, the "auto" dataset is small, the observation is 
> approximately only
> 70. Hence, STATA takes few seconds to calculate the Fischer Exact 
> p-value
> for this 2X5 table(foreign vs rep78).
> My problem is that my dataset is not so big(the number of 
> observations for
> comparison is approximately 2000). This moring, I use -tabulate- 
> to obtain
> the Fischer exact p-value. However, up to now, I still can not get the
> results.
> (This means that for a computer with 312M memory, STATA needs at 
> least 10
> hours for calculating Fischer Exact p-value.)
> I am just wondering whether there is any lister having this kind of
> situation before or not, and how did you solve this situation?
> 
> Up to the moment I send this email, I still can not get the result 
> yet.Thank you very much for any of you who can respond this email. 
> Thanks again.
> 
> JT
> 
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