In both the sign and signed-rank tests, the standard by-hand method of calculating the test statistic would eliminate values equal to the null value for the median (or the null value for the median difference, if these are being used for a paired test). Only values above and below the null median are tested. Because SAS does not print out sample sizes in the test paragraph that reports t, sign, and signed-rank tests, this deletion (if it is occurring) is entirely invisible. Particularly for ordinal data, the quantity of data deleted can be significant. Does anyone know if SAS is using some version of these tests that does not eliminate values equal to the null median? Most SAS test results provide some insight into n or df – these do not.