[R] Fisher test problem

[Ben Bolker]

 <markleeds <at> verizon.net> writes:

> 
>   by definition, the one tailed p-value has to be <= 0.5 so there is 
> still something wrong with your OpenEpi calc. Most likely it's 
> calculating the
> 2 tailed p-value  and then mistakenly multiplying by 2. For example:

For what it's worth, Fisher's exact test with alternative="greater"
(true odds ratio is > 1) does give 0.6273 in R. (Why does a one-tailed
test have to have p<=0.5?  The probability that a test statistic
is greater than some null-hypothesis value can be anywhere
between 0 and 1 ...) It is a 1-tailed test,
but (as has been pointed out) multiplying it by 2 without
truncating at 1 is wrong.

  Ben Bolker