Measured value for the validity of a predictor; often specified in the form of a correlation coefficient.

Correlation coefficient representing the relationship between a test and a criterion measure

The correlation between test scores and an independent measure of the trait (for example, scores on a test of "college potential" and the GPAs the test takers earn when they get to college). Such a correlation is obtained in order to evaluate the extent to which a test measures the intended attribute or trait.

a calculation used in validation studies to indicate the relative predictability of the method

The correlation between a test score and some criterion to which the test is supposed to predict. See also criterion, validity.