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Next: The Wilcoxon Rank-Sum (Mann-Whitney) Up: Nonparametric (Distribution-Free) Inferences Previous: The Sign Test for

The Wilcoxon Signed-Rank Test for Paired Data

A similar test for the median difference in paired data to be zero consists of sorting the absolute values of the differences from smallest to largest, assigning ranks to the absolute values (rank 1 to the smallest, rank 2 to the next smallest, and so on) and then finding the sum of the ranks of the positive differences. If the null hypothesis is true, the sum of the ranks of the positive differences should be about the same as the sum of the ranks of the negative differences. Again, Stataquest will return the p-value of the test.



Jan Lethen
Wed Nov 13 16:20:46 CST 1996