Mann Whitney U Table. Table critical values of the smallest rank sum for the wilcoxon mann whitney test n1 number of elements in the largest sample. It is considered to be the nonparametric equivalent to the two sample independent t test.
Critical values of the mann whitney u one tailed testing n1 n2 α 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 05 0 0 1 2 2 344556778 9 9 10 11. Some investigators interpret this test as comparing the medians between the two populations. Dashes indicate that the sample size is too small to reject the null hypothesis at the chosen α level.
Level of significance level of significance two sided one sided 0 20 0 10 0 10 0 05 0 05 0 025 0 01 0 005 two sided one sided 0 20 0 10 0 10 0 05 0 05 0 025 0 01 0 005.
A mann whitney u test sometimes called the wilcoxon rank sum test is used to compare the differences between two independent samples when the sample distributions are not normally distributed and the sample sizes are small n 30. U obt is the lesser of the two calculated test statistics u 1 u 2. This table provides the quantiles percentiles corresponding to the given probabilities areas listed at the top of each table. Some investigators interpret this test as comparing the medians between the two populations.
