On Thu, 10 Jan 2002 12:00:06 +0100, "Jos Jansen" <[EMAIL PROTECTED]> wrote:
> > "Rich Ulrich" <[EMAIL PROTECTED]> wrote in message > [EMAIL PROTECTED]">news:[EMAIL PROTECTED]... > > On Wed, 09 Jan 2002 08:33:41 GMT, [EMAIL PROTECTED] > > (Jukka Sinisalo) wrote: > > > > > > > > We have two pots with 25 plants each. After an identical treatment we > > > wait for a week, and then calculate how many of the plants died. We > > > repeat this "experiment" 20 times, so we end up with 20 pairs of > > > "survival percantages". > > > > > > We are interested in determining the accuracy/reliability of our > > > method. In other words if in the future we use just one pot of 25 > > > plants, what will be the confidence interval of the result. > > snip > > > "transform the data" - is easy and apt. > > > > Compute the logit and use that in your modeling. With > > the difference of two of them, you have the "log Odds Ratio." > > snip > > Using logits is obvious, but log Odds Ratio is not, given the aim to use > only one pot in the future (not the difference of two). An estimate of the > sum of variance components within and between repeats will be required for > calculating the precision of a single result. > Oh, right. Thanks. I was reading the problem as something different. Misreading it. -- Rich Ulrich, [EMAIL PROTECTED] http://www.pitt.edu/~wpilib/index.html ================================================================= Instructions for joining and leaving this list, remarks about the problem of INAPPROPRIATE MESSAGES, and archives are available at http://jse.stat.ncsu.edu/ =================================================================
