Mann-Whitney U Test

Description

The Mann-Whitney U Test is used to find out whether two different groups or populations can be considered statistically different on an outcome variable or not. Two variables are needed: a categorical variable with exactly 2 groups and an outcome variable measured on the ordinal level or higher. The Mann-Whitney U Test is the preferred test when your data violates the assumptions of an Independent-Samples T-Test. Besides having independent observations in both groups, there are no statistical assumptions to be tested for the Mann-Whitney U Test.