I've calculated the proportion of chicks fledged out of the number of eggs hatched in each year using prop.test() in R. I see that it gives me the proportion fledged, but also the 95% confidence interval, which is what I'm after.
Having read the excellent information from another question on this site here, I understand why I don't have symmetry in my 95% CIs!
- However, how should I report this in a paper?
I've seen people report values as 38% (±0.2%), with an indication that the value in brackets is 95% CI. Obviously this won't work for asymmetrical CIs. Must I report the upper and lower values in these cases?
Best Answer
You should report the lower and upper intervals and also the method used to calculate the interval.
It turns out that there is no 'right' way to calculate confidence intervals for proportions, but instead many competing methods, each with advantages and disadvantages. The lack of a universally correct method stands in contrast to many statistical things that you might put numbers to, like means and standard deviations. For your interval to be fully specified you have to say how you calculated it.