Comparing with Nonparametric Tests
To be added
When it is hard to assume normality, we generally use nonparametric tests.
In such cases, instead of comparing the means of the data, we use other representative statistics (such as the median, rank, etc.) that describes the position of the data.
Table of contents
Wilcoxon Rank Sum Test
Instead of the mean like in parametric tests, Wilcoxon rank sum test is based on the rank of the data.