I've read a few sources that describe ANOVA on ranks, and I am still confused on how the calculation is done, and why.
Specifically:
Is ANOVA on ranks just applying a rank transformation to the data (combined across all groups) and then doing regular ANOVA on the transformed data? If not, how is it different from that?
Why is it valid to assume that the ranks are normally distributed? Wouldn't ranks be uniformly distributed under the null (no effect, no interactions) hypothesis?