[R-sig-eco] quick stats question

[David Hewitt]

Jonathan,

Something to consider...

I don't know what species you are working with, but is it possible
that one sex is more easily captured than the other? If so, simple
comparisons of sex ratio based on raw captures will be polluted by the
difference in capture probability.

Dave Hewitt


> Date: Fri, 11 Feb 2011 09:13:20 -0500
> From: Jonathan Hughes <jonathan.hughes.10 at live.com>
> To: <r-sig-ecology at r-project.org>
> Subject: [R-sig-eco] quick stats question
> Message-ID: <COL112-W6293459ECC7C9034F97585BFEF0 at phx.gbl>
> Content-Type: text/plain
>
> Dear all,
>
> This is both an R and a statistics question. I want to test whether males and females of a given species tend to co-occur in a given sampling unit more frequently than expected by chance. I'm thinking about using a binomial distribution with p as the sex ratio of the entire population. So, even though the population sex ratio is close to 50:50, each sampling unit would have disproportionately more males than females. Given that the test is not about p per se, how would you go about testing this hypothesis?
>
> Thanks!
> Jonathan