[R] Fisher Exact Test

[Patrick Breheny]

On 11/17/2011 06:29 PM, Abraham Mathew wrote:
> I have information on two versions of the same site, and I have data
> on the number of times people filled out a form on each version
> of the site.
>
> Sample data:
>
>                                     Site 1              Site 2
> Filled out form                10                    35
>
> Did not fill out form          50                    40
>
>
> dat2 = matrix(c(10,50,35,40), ncol=2)
> dat2
> fisher.test(dat2)
>
>> fisher.test(dat2)
> 	Fisher's Exact Test for Count Data
>
> data:  dat2
> p-value = 0.0002381
> alternative hypothesis: true odds ratio is not equal to 1
> 95 percent confidence interval:
>   0.09056509 0.54780215
> sample estimates:
> odds ratio
>   0.2311144
>
>
> I'm really not sure if I set up the test properly, but I can
> obviously reject the null hypothesis given the low p-value.
> Site 2 converts better than site 2 at a statistically significant
> threshold.
>
> Am I running my code wrong?

Your code is fine; your conclusion is valid (assuming you mean 
"...better than site 1...").

-- 
Patrick Breheny
Assistant Professor
Department of Biostatistics
Department of Statistics
University of Kentucky