# The Mann-Whitney U: A Test for Assessing Whether Two Independent Samples Come from the Same Distribution

@inproceedings{Nachar2008TheMU, title={The Mann-Whitney U: A Test for Assessing Whether Two Independent Samples Come from the Same Distribution}, author={Nadim Nachar}, year={2008} }

Nadim Nachar Université de Montréal It is often difficult, particularly when conducting research in psychology, to have access to large normally distributed samples. Fortunately, there are statistical tests to compare two independent groups that do not require large normally distributed samples. The Mann‐Whitney U is one of these tests. In the following work, a summary of this test is presented. The explanation of the logic underlying this test and its application are presented. Moreover, the…

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## References

SHOWING 1-10 OF 18 REFERENCES

Comparisons of the Mann-Whitney, Student’s t, and Alternate t Tests for Means of Normal Distributions

- Mathematics, Education
- 1991

AbstractThis paper presents the results of a simulation study to compare the performance of the Mann-Whitney U test, Studentߣs t test, and the alternate (separate variance) t test for two mutually…

Comparative Power of Student T Test and Mann-Whitney U Test for Unequal Sample Sizes and Variances

- Mathematics
- 1987

AbstractA computer program generated power functions of the Student t test and Mann-Whitney U test under violation of the parametric assumption of homogeneity of variance for equal and unequal sample…

Mann–Whitney U test when variances are unequal

- MathematicsAnimal Behaviour
- 2001

The type 1 error rate of the Mann–Whitney U test inflates under unequal variance (heteroscedasticity) and some solutions are suggested.

Power Functions of the t Test and Mann-Whitney U Test Under Violation of Parametric Assumptions

- Mathematics
- 1985

A Monte Carlo method was used to find power functions of the t test and the Mann-Whitney U test under violation of assumptions of normality and homogeneity of variance. These functions showed that…

Do Studies of Statistical Power Have an Effect on the Power of Studies?

- Psychology
- 2004

The long-term impact of studies of statistical power is investigated using J. Cohen's (1962) pioneering work as an example. We argue that the impact is nil; the power of studies in the same journal…

Individual Comparisons by Ranking Methods

- Mathematics
- 1945

The comparison of two treatments generally falls into one of the following two categories: (a) we may have a number of replications for each of the two treatments, which are unpaired, or (b) we may…

Nonparametric Statistics for the Behavioral Sciences.

- Economics
- 1956

This is the revision of the classic text in the field, adding two new chapters and thoroughly updating all others. The original structure is retained, and the book continues to serve as a combined…

Coping strategies in psychiatric clinical research.

- PsychologyJournal of consulting and clinical psychology
- 1981