Hello, I am hoping someone can clarify why I might obtain a quite different value in R & SPSS for a McNemar test I ran.
Firstly, here is the R syntax & output R OUTPUT > mctest <- as.table(matrix(c(128,29,331,430), + ncol =2, dimnames = list(group=c("preMHT","postMHT"), + assault=c("yes","no")))) > mctest assault group yes no preMHT 128 331 postMHT 29 430 > mcnemar.test(mctest,correct=F) McNemar's Chi-squared test data: mctest McNemar's chi-squared = 253.3444, df = 1, p-value < 2.2e-16 SPSS OUTPUT The same data was inputted in SPSS. Regarding the first table SPSS generated - it lists the number of cases in each combination of categories. The diagonal contains the number of cases with the same response on both variables, while the off diagonal contains cases that have different responses on the 2 variables. The overall chisquare value is much lower than the value obtained using R, though still significant. pre02 & post02 pre02 post02 0 1 0 311 20 1 119 9 Test Statistics(b) pre02 & post02 N 459 Chi-Square(a) 69.094 Asymp. Sig. .000 a Continuity Corrected b McNemar Test Any assistance is much appreciated, Bob Green ______________________________________________ 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 and provide commented, minimal, self-contained, reproducible code.