katrina smith <[EMAIL PROTECTED]> writes: > I am trying to find a definition for the two-tailed exact binomial > test but have been unsuccessful. Can you help?
Just read binom.test. The relevant bit is this: (m is the mean == n*p) else if (x < m) { i <- seq(from = ceiling(m), to = n) y <- sum(dbinom(i, n, p) <= d * relErr) pbinom(x, n, p) + pbinom(n - y, n, p, lower = FALSE) } i.e. we take the lower tail, including the value observed + the part of the upper tail where the binomial density is less than or equal to that of x (with a little fuzz added in). Symmetrically for observations in the upper tail of course. If you were looking for an "official" definition of the two sided exact test, I don't think one exists. R's version is equivalent to the likelihood ratio test, but there are alternatives (tail-balancing, doubling the one-sided p, and maybe more). -- O__ ---- Peter Dalgaard Ă˜ster Farimagsgade 5, Entr.B c/ /'_ --- Dept. of Biostatistics PO Box 2099, 1014 Cph. K (*) \(*) -- University of Copenhagen Denmark Ph: (+45) 35327918 ~~~~~~~~~~ - ([EMAIL PROTECTED]) FAX: (+45) 35327907 ______________________________________________ R-help@stat.math.ethz.ch mailing list https://stat.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide! http://www.R-project.org/posting-guide.html