Standard Article


  1. Frederick L. Coolidge,
  2. Daniel L. Segal

Published Online: 30 JAN 2010

DOI: 10.1002/9780470479216.corpsy0787

Corsini Encyclopedia of Psychology

Corsini Encyclopedia of Psychology

How to Cite

Coolidge, F. L. and Segal, D. L. 2010. Reliability. Corsini Encyclopedia of Psychology. 1–2.

Author Information

  1. University of Colorado at Colorado Springs

Publication History

  1. Published Online: 30 JAN 2010


Reliability refers to the consistency or stability of a measurement. A test with good reliability means that the respondent will obtain the same score upon repeated testing, as long as no other extraneous factors affect the score. In actuality, a respondent will rarely obtain exactly the same score over repeated testing, because repeated assessments of any phenomenon are likely to be affected by chance errors. Thus, the goal of testing is to minimize chance errors and maximize the reliability of the measurement, with the recognition that a perfectly reliable measure is rarely attainable.


  • measurement;
  • psychometrics;
  • reliability;
  • statistics;
  • validity