Sometimes, when we do research, we have to use measures of uncertain or unknown validity because there simply aren't any better measures available. This form of validity is important in achievement testing. For example, test of 9th grade mathematics achievement will have high content validity to the extent that the test items are representative, in both types and proportion of items, of the content of the 9th grade mathematics curriculum. Unlike other forms of validity, content validity is not expressed as a correlation coefficient. Content validity is arrived at through an objective comparison of the test items with the whole of the curriculum content.
Content validity is more objective than face validity, and a more useful measure.
For example, we might predict 4th graders' social adjustment from their first grade reading achievement test scores. Another example is the use of the GRE test to predict academic performance in graduate school. The SAT and ACT tests, of course, have high predictive validity for academic performance in college. The distinction between concurrent and predictive validity depends on when the criterion measure is administered. If the criterion measure is given at the same time as the standardized measure, this is concurrent validity.