Standard Article


  1. K. Gauvreau

Published Online: 15 JUL 2005

DOI: 10.1002/0470011815.b2a15174

Encyclopedia of Biostatistics

Encyclopedia of Biostatistics

How to Cite

Gauvreau, K. 2005. Variance. Encyclopedia of Biostatistics. 8.

Author Information

  1. Harvard School of Public Health, Boston, MA, USA

Publication History

  1. Published Online: 15 JUL 2005


The variance of a random variable is the average value of the squared deviation from the mean. Its square root is the standard deviation. In a sample of size n, the corresponding sample measure usually has a divisor n − 1 rather than n.


  • moment;
  • dispersion;
  • standard deviation;
  • unbiasedness