How do you interpret the Mann-Whitney p-value?

How do you interpret the Mann-Whitney p-value?

Usually, a significance level (denoted as α or alpha) of 0.05 works well. A significance level of 0.05 indicates a 5% risk of concluding that a difference exists when there is no actual difference. If the p-value is less than or equal to the significance level, the decision is to reject the null hypothesis.

How do you present Mann-Whitney results on a graph?

On the Display tab of the Mann-Whitney Test dialog box, select the graphs to include in your output. Use an individual value plot to examine the spread of the data and to identify any potential outliers.

How do you use the Mann-Whitney test in Minitab?

Example of Mann-Whitney Test

1. Open the sample data, HighwayPaint. MTW.
2. Open the Mann-Whitney Test dialog box. Mac: Statistics > 2-Sample Inference > Mann-Whitney.
3. From the drop-down list, select Each sample is in its own column.
4. In Sample 1 enter Brand A.
5. In Sample 2, enter Brand B.
6. Click OK.

How do you read a Mann-Whitney 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 a statistically significant p value for the Mann-Whitney U test imply?

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.

What is critical value in Mann-Whitney test?

The critical value of U can be found in the table below. To determine the appropriate critical value we need sample sizes (for Example: n1=n2=5) and our two-sided level of significance (α=0.05). For Example 1 the critical value is 2, and the decision rule is to reject H0 if U < 2.

How is the Mann Whitney statistic calculated in MINITAB?

The Mann-Whitney statistic (W-Value) is the sum of the ranks of the first sample. Minitab calculates the Mann-Whitney statistic as follows: Minitab ranks the two combined samples.

How to interpret the results of the Mann Whitney test?

Interpret the key results for Mann-Whitney Test. 1 Step 1: Determine a confidence interval for difference between two population medians. First, consider the difference in the sample medians, and then 2 Step 2: Determine whether the difference is statistically significant. 3 Step 3: Identify outliers.

When to use Wilcoxon signed rank instead of Mann Whitney U?

The participant cannot be in both groups. If you do not have independence of observations, it is likely you have “related groups”, which means you will probably need to use a Wilcoxon signed-rank test instead of the Mann-Whitney U test (see our Wilcoxon signed-rank test in Minitab guide).

When to use independent t test in MINITAB?

Our independent variable, which we have labelled Gender in Minitab, contains two groups: “Males” and “Females”. An independent t-test was used to determine whether there was a statistically significant difference in mean engagement between males and females.