I am working on my thesis and my supervisor wanted me to calculate cohen's d for my significant results. I am using SPSS and I was able to calculate Cohen's d using an external site. My independent variable is group (HRD or NRD). I was able to enter in the means and standard deviations for my two groups into this site to get the Cohen's d (as it is not possible to do so on SPSS). I have two results that are significant, however I calculated them using independent Mann Whitney U tests and the results I have only provide one mean and one SD.
I was just wondering if it is at all possible to calculate Cohen's d from nonparametric statistics.