Chapter 12. The Wilcoxon Signed-Rank Test

  • 12.1 Introduction 253

  • 12.2 Synopsis 253

  • 12.3 Examples 254

  • 12.4 Details & Notes 260

12.1 Introduction

The Wilcoxon signed-rank test is a non-parametric analog of the one-sample t-test (Chapter 4). The signed-rank test can be used to make inferences about a population mean or median without requiring the assumption of normally distributed data. As its name implies, the Wilcoxon signed-rank test is based on the ranks of the data.

One of the most common applications of the signed-rank test in clinical trials is to compare responses between correlated or paired data, such as testing for significant pre- to post-study changes of a non-normally distributed evaluation measurement. The layout is the same as that for ...

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