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Mathematics

Nonparametric Statistical Tests: The Wilcoxon Rank-Sum Test

Quick fact

The Wilcoxon rank-sum test, also known as the Mann-Whitney U test, converts data to ranks, making it highly robust to outliers and ideal for skewed distributions or ordinal data, without assuming normality.

Why this is interesting

When your data is heavily skewed or has extreme outliers, the classic t-test might fail you. What if there's a robust alternative that doesn't require a normal distribution?