The face validity of survey instruments and tests used in psychometrics , is assessed by cursory review of the items (questions) by untrained individuals. The individuals make their judgments on whether the items are relevant. For example, a researcher developing an IQ-test might ask his friends and relatives to read the questions and make their judgements.
The face validity is a qualitative measure of validity; it is not quantified with statistical methods. Of all validity measures, the face validity is normally considered as the least scientific measure - because untrained individuals chosen on the basis of convenience are involved, and because this measure is subjective and not quantifiable.
See also: content validity .