Wilcoxon Signed-Rank Test Calculator
This calculator performs the Wilcoxon signed-rank test, a non-parametric alternative to the paired t-test. Use this when comparing two related measurements that don't meet normality assumptions.
When to Use
- Paired/related samples (same subjects measured twice)
- Differences are not normally distributed
- Data is ordinal or continuous with outliers
How It Works
- Calculate differences between paired values
- Rank the absolute differences (ignore zeros)
- Sum ranks for positive and negative differences separately
- The smaller sum is the W statistic
Null Hypothesis
H₀: The median difference between pairs is zero
