Mann–Whitney U test
Prueba U de Mann-Whitney
- Date
- 1947 · confidence high
- Place
- Ohio State University, Columbus, Ohio, United States
- Credited to
- Henry Mann and Donald Ransom Whitney
- Field
- Knowledge & symbols
What was discovered
Mann and Whitney published a rigorous analysis of a non-parametric test for comparing two independent samples, establishing its asymptotic normality and probability tables, which turned it into a practical alternative to the t-test when normality cannot be assumed.
Wilcoxon had proposed an equivalent rank-sum test in 1945, but with tables limited to small samples; Mann and Whitney gave it its full theoretical grounding and more general tables in 1947.
What it led to
- The reference non-parametric test for comparing two groups
- Widespread use in medicine, psychology and social science
Built on
- Frank Wilcoxon's signed-rank and rank-sum tests (1945)