Mann-Whitney Calculations Test?

Question

i have ranked up my values from 1 to 10. and now that i am working out the total for the two sets they are the same. This means the Ra + Rb is not equal to the (na+nb)(na+nb+1) /2

what has gone wrong...

could it be that i need to a spearmans test

Answer 1

I have done this test in Psychology.

It does not mean you have done anything wrong, it just means that you have to reject your experimental hypothesis.

Although, it may be useful to carry out a spearmans rank test just to double check and verify your final results.