# Mann-Whitney U Test - Interpretation

I have conducted a survey and would like to assess whether men compared to women differ in their attitudes. At a glance, the means differ quite much, which is why I wanted to prove it statistically.

For this reason, I conducted a Mann-Whitney test, as my dependent variables are ordinal and the distributions are non-normal. However, now I am not sure how to interpret the results. As mentioned above, I ideally want to make a statement that attitudes between men and women differ significantly (and that men/women show a more positive attitude towards something).

Now, if I display the mean ranks for both groups and find a significant p, can I derive such a statement depending on the size of the mean ranks?

I found a study of my professor in which he put the mean/SE of two groups next to the Mann-Whitney U and p-value and concluded that they are significantly lower/higher. However, I also read multiple times that this is not how the Mann-Whitney U test works and should be interpreted. Long story short - how can I prove that the attitudes are significantly different and more/ less positive between two groups?

Thanks so much!

• "At a glance, the means differ quite much, which is why I wanted to prove it statistically." You generally need to fix the test you are using before knowing the data. If you run tests only if it looks like you have a difference (or conditionally on any decision based on your data), you already have invalidated any test and you can't "prove" anything. So generally looking at the data and then trying to find significance for something that you see in the data is not how proper testing works. Commented Sep 5, 2023 at 10:27