Wilcoxon Sign Test - SoojungHong/StatisticalMind GitHub Wiki

The Wilcoxon Signed Rank test is a non-parametric analysis that statistically compared of the average of two dependent samples and assess for significant differences.

The Wilcoxon sign test is the non-parametric alternative of the dependent samples t-test.

Questions Answered:

Are test scores different from 4th grade to 5th grade on the same students?

Does a particular diet drug have an effect on BMI when tested one the same individuals?

Assumptions:

Data comes from two matched, or dependent, populations.

The data is continuous.

Because it is a non-parametric test it does not require a special distribution of the dependent variable in the analysis.

The Wilcoxon Sign test is a repeated measures test of dependency. This test is mathematically similar to conducting a Mann-Whitney U-test (which is sometimes also called Wilcoxon 2-sample t-test). It is also similar to the basic principle of the dependent samples t-test, because just like the dependent samples t-test the Wilcoxon sign test, tests the difference of observations when the observations are matched.