Wilcoxon's signed‐rank statistic: what null hypothesis and why it matters |
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Authors: | Heng Li Terri Johnson |
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Affiliation: | Center for Devices and Radiological Health, US Food and Drug Administration, , Silver Spring, MD, 20993 USA |
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Abstract: | In statistical literature, the term ‘signed‐rank test’ (or ‘Wilcoxon signed‐rank test’) has been used to refer to two distinct tests: a test for symmetry of distribution and a test for the median of a symmetric distribution, sharing a common test statistic. To avoid potential ambiguity, we propose to refer to those two tests by different names, as ‘test for symmetry based on signed‐rank statistic’ and ‘test for median based on signed‐rank statistic’, respectively. The utility of such terminological differentiation should become evident through our discussion of how those tests connect and contrast with sign test and one‐sample t‐test. Published 2014. This article is a U.S. Government work and is in the public domain in the USA. |
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Keywords: | matched‐pairs design one‐sample t‐test sign test pedagogy |
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