What does a Mann-Whitney test tell you?

What does a Mann-Whitney test tell you?

The Mann-Whitney U test is used to compare whether there is a difference in the dependent variable for two independent groups. It compares whether the distribution of the dependent variable is the same for the two groups and therefore from the same population.

How do you interpret the Mann Whitney p-value?

Because the assumptions are now verified, the Mann-Whitney test can be conducted. If the p-value is below the usually agreed alpha risk of 5 percent (0.05), the null hypothesis can be rejected and at least one significant difference can be assumed. For the call times, the p-value is 0.0459 – less than 0.05.

Does Mann Whitney compare means?

The Mann-Whitney test compares the mean ranks — it does not compare medians and does not compare distributions.

What is the Mann-Whitney test commonly used to compare?

The Mann-Whitney U test is used to compare differences between two independent groups when the dependent variable is either ordinal or continuous, but not normally distributed.

What is the null hypothesis for Mann-Whitney U test?

The null hypothesis for the test is that the probability is 50% that a randomly drawn member of the first population will exceed a member of the second population. Another option for the null hypothesis is that the two samples come from the same population (i.e. that they both have the same median).

What is the null hypothesis for Mann-Whitney test?

How do I report Mann Whitney U results?

In reporting the results of a Mann–Whitney test, it is important to state:

1. A measure of the central tendencies of the two groups (means or medians; since the Mann–Whitney is an ordinal test, medians are usually recommended)
2. The value of U.
3. The sample sizes.
4. The significance level.

Does Mann-Whitney U test use mean or median?

It is often presented as an alternative to a t test when the data are not normally distributed. Whereas a t test is a test of population means, the Mann-Whitney test is commonly regarded as a test of population medians.

How do you read a Mann-Whitney U test table?

Mann-Whitney Table

1. Alpha = .001 (two-tailed)
2. Alpha = .005 (two-tailed)
3. Alpha = .01 (two-tailed)
4. Alpha = .02 (two-tailed)
5. Alpha = .05 (two-tailed)
6. Alpha = .10 (two-tailed)
7. Alpha = .20 (two-tailed)

What does the Mann Whitney test tell you?

The Mann-Whitney U test is used to compare whether there is a difference in the dependent variable for two independent groups. It compares whether the distribution of the dependent variable is the same for the two groups and therefore from the same population.

When to use Wilcoxon Mann Whitney test?

The dependent variable is ordinally scaled instead of interval or ratio.

The assumption of normality has been violated in a t-test (especially if the sample size is small.)

The assumption of homogeneity of variance has been violated in a t-test

What does a Mann Whitney test show?

The Mann-Whitney U Test is a statistical test used to determine if 2 groups are significantly different from each other on your variable of interest. Your variable of interest should be continuous and your 2 groups should have similar values on your variable of interest.

What is Mann Kendall test?

The Mann-Kendall trend test is a non parametric way to detect a trend in a series of values. Available in Excel using the XLSTAT statistical software. Mann-Kendall trend test is a nonparametric test used to identify a trend in a series, even if there is a seasonal component in the series.