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Statistical Sirens: The Allure of Nonparametrics

Douglas H. Johnson*

Abstract: Although nonparametric statistical methods have a role to play in the analysis of data, often their virtues are overstated and their deficiencies overlooked. A recent Special Feature in Ecology advocated nonparametric methods because of an erroneously stated advantage that they require no assumptions regarding the distribution underlying the observations. The present paper points out some often-ignored features of nonparametric tests comparing two means, and advocates parameter estimation as a preferred alternative to hypothesis testing in many situations.

Key words: Hypothesis testing; nonparametric methods; normal distribution; parameter estimation; Wilcoxon-Mann-Whitney test vs. t test.

This resource is based on the following source (Northern Prairie Publication 0934): 
Johnson, Douglas H.  1995.  Statistical sirens: the allure of 
     nonparametrics.  Ecology 76(6):1998-2000.

This resource should be cited as: 

Johnson, Douglas H.  1995.  Statistical sirens: the allure of 
     nonparametrics.  Ecology 76(6):1998-2000.  Jamestown, ND: 
     Northern Prairie Wildlife Research Center Online.  
     http://www.npwrc.usgs.gov/resource/methods/nonparam/index.htm  
     (Version 05OCT2000).

Table of Contents

* Northern Prairie Science Center, National Biological Service, Jamestown, North Dakota 58401 USA
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