thanks ben: i think my example makes sense but my terminology of one
tailed two tailed was wrong or flipped or whatever. in fact, that's
why i gave the example. i wasn't remembering the terminology because
it's been too long since i stepped in a classroom ( 8 years ).
On Sat, Mar 21, 2009 at 10:42 PM, Ben Bolker wrote:
<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
______________________________________________
R-help@r-project.org mailing list
https://stat.ethz.ch/mailman/listinfo/r-help
PLEASE do read the posting guide
http://www.R-project.org/posting-guide.html
and provide commented, minimal, self-contained, reproducible code.
______________________________________________
R-help@r-project.org mailing list
https://stat.ethz.ch/mailman/listinfo/r-help
PLEASE do read the posting guide http://www.R-project.org/posting-guide.html
and provide commented, minimal, self-contained, reproducible code.
