I have a sample and in my study were going to compare 2 or 3 samples.
If I am going to compare 2 groups, I need to know if one of the sample has a normal distribution and another doesn't, can I run an parametric or nonparametric test?
Same for 3 samples, if 2 sample has normal distribution an 1 doesnt. Or, of 3 samples, 1 doesnt have normal distibribution and the others has, I run a parametric or non parametric test?
Thank you.