Nonparametric Tests

Contents

Page 1
Introduction
Learning Objectives

Page 2
When to Use a Nonparametric Test
Using an Ordinal Scale
When the Outcome is a Rank
When There Are Outliers
Limits of Detection
Advantages of Nonparametric Tests

Page 3
Introduction to Nonparametric Testing
Assigning Ranks

Page 4
Mann Whitney U Test (Wilcoxon Rank Sum Test)
Test Statistic for the Mann Whitney U Test
Table of Critical Values for U

Page 5
Tests with Matched Samples
The Sign Test
Test Statistic for the Sign Test
Table of Critical Values for the Sign Test
Computing P-values for the Sign Test
One-Sided versus Two-Sided Test
When Difference Scores are Zero

Page 6
Wilcoxon Signed Rank Test
Test Statistic for the Wilcoxon Signed Rank Test
Table of Critical Values of W

Page 7
Tests with More than Two Independent Samples
The Kruskal-Wallis Test
Test Statistic for the Kruskal Wallis Test
Critical Values of H for the Kruskal Wallis Test
Critical Values of the χ2 Distribution

Page 8
Summary
Mann Whitney U Test
Sign Test
Wilcoxon Signed Rank Test
Kruskal Wallis Test

Page 9
References

Content ©2016. All Rights Reserved.
Date last modified: May 24, 2016.
Wayne W. LaMorte, MD, PhD, MPH

Boston University School of Public Health