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Half-Normal Distribution

  1. R. H. Byers

Published Online: 15 JUL 2005

DOI: 10.1002/0470011815.b2a15052

Encyclopedia of Biostatistics

Encyclopedia of Biostatistics

How to Cite

Byers, R. H. 2005. Half-Normal Distribution. Encyclopedia of Biostatistics. 4.

Author Information

  1. Atlanta, GA, USA

Publication History

  1. Published Online: 15 JUL 2005


The half-normal distribution occurs when sampling from a normally distributed population where the signs of the negative observations are lost or are not relevant. This article includes the formulae for the probability density, mean, variance, skewness and kurtosis, and the maximum likelihood estimator of the distribution's parameter.


  • moments;
  • maximum likelihood;
  • clinical trials