Test reliability refers to the extent to which a test measures without error. It is highly related to test validity. Test reliability can be thought of as precision, the extent to which measurement occurs without error. Test validity can be thought of as accuracy, the extent to which the test measures the hypothesized underlying construct. Reliability is not a constant property of a test and is better thought of as different types of reliability for different populations at different levels of the construct being measured. For example, the consistency in score for a measure of intelligence when observations are obtained at two different times in a sample of individuals performing in the superior range is one estimate of reliability.
The types of reliability correspond to the methods of estimating the influence of different sources of error. When the...
References and Readings
- American Educational Research Association and the American Psychological Association. (1999). Standards for educational and psychological tests. Washington, DC: American Psychological Association.Google Scholar
- Franzen, M. D. (2000). Reliability and validity in neuropsychological assessment (2nd ed.). New York: Plenum.Google Scholar