Mann-Whitney U Test

(Equivalent to the Wilcoxon rank sum test.)

Use this form if you have calculated the Mann-Whitney test statistics n1, n2, and U:
n1:
n2:
U:

Use this form if you want the statistics calculated for you. Paste into each box a list of numbers:
dataset 1:
dataset 2:
Use "." for decimals, not ",".

If your numbers are large, be patient -- the calculation may take a minute or two. Don't reload -- that will only slow the response down.

Software

This page uses the program utest. Source code for utest is available here. This code has only been used under linux. It should work without much change under other operating systems, but this has not been tested.

Here is a table of critical values of U. utable.pl is a perl script that uses utest to generate a table of critical values for U.

Leon Avery (lavery3@vcu.edu)
Last modified: Sun Jan 7 10:26:06 2007