The Mann-Whitney Nonparametric Test in the Role of a Location Test
This Demonstration uses the Mann–Whitney test, a standard nonparametric test, to test whether the means or medians of two groups are equal. Consider and test the null hypothesis for median difference: . You can vary the hypothesized to find the range where is not rejected. For those values, the value of from the null hypothesis is not considered to be significantly different from the true value.