The statistics (U or U') used in the Mann-Whitney U test, measure _________. Group of answer choices the separation between the two groups the direction of the differences between pairs of scores the power of the experiment the differences between the means of the two groups

In a test with two groups, the smaller value between the statistics U and U' points to the research hypothesis, while the larger value points to the alternative hypothesis.

The formula to calculate U and U' is:

[tex]U = n_1 \times n_2 + \frac{n_1(n_1+1)}{2} - R_1[/tex]

[tex]U' = n_1 \times n_2 + \frac{n_2(n_2+1)}{2} - R_2[/tex]

Take, for instance;

The values of U and U' in a test where the research hypothesis of two populations are not equal are:

[tex]U = 0[/tex]

[tex]U' = 22[/tex]

Recall that, the smallest of the 2 value supports the research hypothesis.

This means that [tex]U = 0[/tex] shows that the difference in the population is 0.