[R] general question on binomial test / sign test

[Greg Snow]

Try thinking this one through from first principles, you are essentially saying that your null hypothesis is that you are flipping a fair coin and you want to do a 2-tailed test.  You then flip the coin exactly once, what do you expect to happen?  The p-value of 1 just means that what you saw was perfectly consistent with what is predicted to happen flipping a single time.

Does that help?

If not, please explain what you mean a little better.

-- 
Gregory (Greg) L. Snow Ph.D.
Statistical Data Center
Intermountain Healthcare
greg.snow at imail.org
801.408.8111


> -----Original Message-----
> From: r-help-bounces at r-project.org [mailto:r-help-bounces at r-
> project.org] On Behalf Of Kay Cichini
> Sent: Wednesday, September 01, 2010 3:06 PM
> To: r-help at r-project.org
> Subject: [R] general question on binomial test / sign test
> 
> 
> hello,
> 
> i did several binomial tests and noticed for one sparse dataset that
> binom.test(1,1,0.5) gives a p-value of 1 for the null, what i can't
> quite
> grasp. that would say that the a prob of 1/2 has p-value of 0 ?? - i
> must be
> wrong but can't figure out the right interpretation..
> 
> best,
> kay
> 
> 
> 
> 
> 
> -----
> ------------------------
> Kay Cichini
> Postgraduate student
> Institute of Botany
> Univ. of Innsbruck
> ------------------------
> 
> --
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