Wilcoxon rank sum test
(aka Mann-Whitney U test)
- Non-parametric equivalent of parametric t-test for
2 independent samples (unpaired t-test) - Suppose the waiting time (in days) for cataract
surgery at two eye clinics are as follows:
Patients at clinic A
(nA=18)
1, 5, 15, 7, 42, 13, 8, 35, 21,
12, 12, 22, 3, 14, 4, 2, 7, 2
Patients at clinic B
(nB=15)
4, 9, 6, 2, 10, 11, 16, 18, 6, 0,
9, 11, 7, 11, 10