arnold on Sep 16, 2008
Discriminant validity – describes the degree to which the operationalization is not similar to (diverges from) other operationalizations that it theoretically should not be similar to.
Campbell and Fiske (1959) introduced the concept of discriminant validity within their discussion on evaluating test validity. They stressed the importance of using both discriminant and convergent validation techniques when assessing new tests. A successful evaluation of discriminant validity shows that a test of a concept is not highly correlated with other tests designed to measure theoretically different concepts.
In showing that two scales do not correlate, it is necessary to correct for attenuation in the correlation due to measurement error.