jamovi

Hi!

When I performed an Mann-Whitney U test on some data I wanted to see the effect size, at first it was showed Cohen's d "0.06" and all was good but then I wanted to perform it again later on and now it's reported as "Rank biserial correlation" with an effect size as "0.03"... And I don't know what has changed it my data material. All that I can think of is that I changed the items to continous scale instead of ordinal scale. But when I change back to ordinal scale now it still report the effect size as "Rank biserial correlation"...

Anyone that can help me?

Did you by any chance updated jamovi in the meantime? We recently updated the effect sizes in the t-tests to use more appropriate types of effect sizes for different tests. In this update we changed the effect size of the mann-whitney U test from cohen's d to a rank biserial correlation (which is more appropriate in this case).

Oh! Yeah I can see now when we started I used the 1.1.9.0 version and now the Jamovi version 1.2.27.0. It must have updated without me noticing. Thank you for your answer!!!