AS and A Level Psychology: Which formula should be used for Mann Whitney U?

Following feedback from teachers, we can now clarify which formula students should use for the Mann Whitney U test. 

We can confirm that students need to be familiar with the following formula:

This is the only formula students need to know in relation to the Mann Whitney U test. This formula will be used in our assessments from 2020 onwards. Please be aware that any previous exam papers referring to Mann Whitney U, will show an alternative formula.

If you want support with teaching inferential statistics we have a dedicated student workbook and a blog outlining ways to teach this part of the course.