Donald Burrill <[EMAIL PROTECTED]> wrote in message
[EMAIL PROTECTED]">news:[EMAIL PROTECTED]...
> On Sun, 28 Oct 2001, Melady Preece wrote:
>
> > Hi. I want to compare the percentage of correct identifications (taste
> > test) to the percentage that would be correct by chance 50%? (only two
> > items being tasted). Can I use a t-test to compare the percentages?
> > What would I use for the s.d. for by chance percentage? (0?)
>
> Standard comparison would be the formal Z-test for a proportion; see
> any elementary stats text. If you have a reasonably large sample size,
> use the normal approximation to the binomial; if you have a small
> sample, it may be necessary to use the binomial distribution itself,
> which is considerably more tedious unless you have comprehensive tables.
>
> Sounds as though you'd wish to test H0: P = .50 vs. H1: P <> .50.
I'd kind of expect them to want this one to be one tailed - it would
seem strange to be interested in the circumstance where tastebuds do
worse than chance (well, it'd be kinky and fun, but would it change
your action from no difference? I can conceive of it, but I'd bet not.)
Glen
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