Non-parametric two groups

Null hypothesis (H0): The medians of the differences between the two group samples are equal.

  • Wilcoxon: paired data. Assumes that the differences between samples are symmetrical with respect to the median.
  • Binomial Sign: paired data. Does not assume symmetry but is less powerfull than Wilcoxon.
  • Mann-Whitney-U: unpaired data.
References

  • Wilcoxon: Wilcoxon, F. (1945). Individual comparisons by ranking methods. Biometrics bulletin, 80-83.

  • Mann-Whitney-U: Mann, H. B., Whitney, D. R. (1947). On a test of whether one of two random variables is stochastically larger than the other. The annals of mathematical statistics, 50-60.