Preparing a paper for a medical journal. Using the prop.test() function in R (v2.4.0)
to compare two groups' response to data like the following. A sample of 100 individuals from Population I, 18 with positive readings from a certain test, vs. A sample of 148 individuals from Population II, 61 with positive readings. Results look like this: R version 2.4.0 Patched (2006-11-25 r39997) ...... > prop.test(c(18,61),c(100,148)) 2-sample test for equality of proportions with continuity correction data: c(18, 61) out of c(100, 148) X-squared = 13.7676, df = 1, p-value = 0.0002069 alternative hypothesis: two.sided 95 percent confidence interval: -0.3498963 -0.1144280 sample estimates: prop 1 prop 2 0.1800000 0.4121622 Presumably the p-value measures that the likelihood that the two populations have the same proportion of response. My question is this. The reviewer of the paper has asked for a reference on the algorithm used to compute the p-value. The R Reference Manual is not clear on this. Is this a standard algorithm that can be quoted by name (e.g., "Two-sample T Test")? I do note that the manual quotes a 1927 article by E.B. Wilson. Is the method of computation explained there? Thank you for any assistance you can provide. George Heine ghe...@mathnmaps.com ______________________________________________ R-help@r-project.org mailing list https://stat.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide http://www.R-project.org/posting-guide.html and provide commented, minimal, self-contained, reproducible code.