Wilcoxon Rank-Sum Table

In the following tables n1 is the size of the smaller sample and n2 is the size of the larger sample. See Wilcoxon Rank-Sum Test for details. Note that α for a one-tail test (lower tail) is equivalent to 2α for a two-tail test.

Alpha = .01 (two-tailed)

Wilcoxon Rank-Sum Table, alpha = .01

Alpha = .05 (two-tailed)

Wilcoxon Rank-Sum Table, alpha = .05

Alpha = .20 (two-tailed)

Wilcoxon Rank-Sum Table, alpha = .20

9 Responses to Wilcoxon Rank-Sum Table

  1. Chrissy says:

    If I have a sample size of 9 and 18 can I still use the ‘=NORM.DIST(A1,A6, B8, TRUE) function described for calculating P values for larger sample sizes?

    • Charles says:

      Chrissy,
      The normal approximation is probably ok, but it is marginal. I wouldn’t be surprised that the result is more or less the same with that using the table of critical values.
      Charles

      • Chrissy says:

        Thanks very much for your comment, also your whole webpage has helped me no end so thanks very much, it’s a brilliant resource!
        When I used the NORM.DIST function my W’ value was larger than W (so I actually used 1- NORM.DIST…) and Wcrit value was more or less the same as my W’ value, rather than W. Presumably this is okay?
        Many thanks

  2. Navdeep Singh says:

    Hello Sir,
    My n1 and n2 are 50. I dont know how to find value corresponding to these values in table.
    Please help me.

    • Charles says:

      Navdeep,
      For values above 20, you don’t need to use the table. Instead you should use the normal approximation as described on the website.
      Charles

  3. Sadegh says:

    Hi Charlez,
    I am little confused, why the result of table is different from table in page 1097 in this link: http://www.stat.ufl.edu/~athienit/Tables/tables.pdf

    • Charles says:

      Hi Sadegh,
      There is some fluctuation between statistical tables from different sources. I checked the TL values at alpha = .05, two-tails, for n2 = 10. The values in the table in the site you referenced are generally 1 unit higher than in the table on my site. I don’t know why the two sources got different values. The values on my site appear in many references, including Howell’s textbook, Statistical Methods for Psychology.
      Charles

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