Standard Article


  1. W. A. Link

Published Online: 15 JUL 2005

DOI: 10.1002/0470011815.b2a15166

Encyclopedia of Biostatistics

Encyclopedia of Biostatistics

How to Cite

Link, W. A. 2005. Unbiasedness. Encyclopedia of Biostatistics. 8.

Author Information

  1. US Geological Survey, Laurel, MD, USA

Publication History

  1. Published Online: 15 JUL 2005


Unbiasedness is defined and illustrated as a criterion in estimation and hypothesis testing. Limitations of the criterion are illustrated by examples: that unbiasedness is not transformation invariant, that unbiased estimators need not exist, nor be unique, and that even when a unique unbiased estimator exists, it might be clearly unreasonable.


  • estimation;
  • hypothesis testing;
  • jackknife;
  • mean squared error;
  • optimality criteria;
  • UMVUE;
  • unbiasedness