ABSTRACT
This chapter discusses the types of validity and then introduces basic statistical concepts. Construct validity, then, refers to the correspondence between the constructs for a characteristic and the actual measurement that is being used to measure that characteristic. Calibration is an action taken to improve the criterion validity of a measurement device. Criterion validity is one of the most convincing ways to establish the validity of a measurement, but it requires that a criterion measurement be available to use for comparison. The simplest evidence of validity is termed content validity, also sometimes called face validity or logical validity. The validity of a measurement is its most important quality. Validity is the extent to which a measurement measures what it is supposed to measure, with an acceptable degree of error, and is applied appropriately.
