I know the formula for the effect size is Z/squaroot of N.

My question is, does N refer to the numbe of participant (N=10) or should I multiply the number of participant with 2..so N = 20?

For mann whitney U, i should add the number of participants in both group, but I am not sure should i multiply the number of participant in wilcoxon.

2) DO i need to calculate the effect size for all conditions? or only thos with significant diffetence (P<.05)

3) DO i ignore the 'negative' sign when reporting the effect size?

Thanks!