[R] (no subject)

Anon. bob.ohara at helsinki.fi
Sun Oct 31 09:01:05 CET 2004

fang lai wrote:

>Dear all,
> I have several questions regarding fisher.test() in
>R, and I'd highly appreciate any help with it.
> I have a group of observations, each having people's
>income, and an indicator of whether selected in or out
>a program. I want to test the difference between
>income of people who are in and out.
> Because the distribution is far from normal, I decide
>to use the fisher's exact test, using either mean or
>rank as statistics.
> Question 0 is: Can I do this test using fisher.test()
>in R?
The answer is "no".  I think you have mis-understood the purpose of 
Fisher's exact test: read (and understand!) the description in the help 

If your data were normall distributed, then you could use a t-test 
(t.test()).  As you are not happy with the normality assumption, you 
could try an equivalent non-paramteric test, such as the Wilcoxon test 
(wilcox.test()), also known as a Mann-Whitney test.  I would recommend 
that you make sure you understand how the test works first.


Bob O'Hara
Department of Mathematics and Statistics
P.O. Box 68 (Gustaf Hällströmin katu 2b)
FIN-00014 University of Helsinki

Telephone: +358-9-191 51479
Mobile: +358 50 599 0540
Fax:  +358-9-191 51400
WWW:  http://www.RNI.Helsinki.FI/~boh/
Journal of Negative Results - EEB: www.jnr-eeb.org

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