Standard Article

Balanced Incomplete Block Designs

  1. Sally Freels

Published Online: 15 JUL 2005

DOI: 10.1002/0470011815.b2a10086

Encyclopedia of Biostatistics

Encyclopedia of Biostatistics

How to Cite

Freels, S. 2005. Balanced Incomplete Block Designs. Encyclopedia of Biostatistics. 1.

Author Information

  1. University of Illinois, Chicago, IL, USA

Publication History

  1. Published Online: 15 JUL 2005


Random assignment of treatments within homogeneous blocks is an effective way to eliminate confounding due to differences between blocks when analyzing treatment differences. A complete block design includes observations within every combination of blocking factors. Balanced incomplete block designs provide a more efficient alternative in which all combinations are not represented, but every pair of blocks appears equally often.


  • random treatment assignment;
  • analysis of variance;
  • block designs