Standard Article

Mean Deviation

  1. Frank Hampel

Published Online: 15 JUL 2005

DOI: 10.1002/0470011815.b2a15086

Encyclopedia of Biostatistics

Encyclopedia of Biostatistics

How to Cite

Hampel, F. 2005. Mean Deviation. Encyclopedia of Biostatistics. 5.

Author Information

  1. University of Zurich, Zurich, Switzerland

Publication History

  1. Published Online: 15 JUL 2005


The mean deviation of a set of measurements is the mean of the absolute deviations from some location measure, which may be the sample mean or median, a population mean or some other constant. Its relation to the standard deviation is described. For normal samples, the standard deviation is a more efficient estimator of the population standard deviation, but the reverse is true for some forms of contaminated distributions.


  • standard deviation;
  • ARE;
  • efficiency;
  • contamination;
  • robustness