Is a behavioral measure the best estimate of behavioral parameters? Perhaps not.

Abstract

In many areas of psychological research various measurement procedures are employed in order to obtain estimates of some set of parameter values. A common practice is to validate one measurement device by demonstrating its relationship to some criterion. However, in many cases the measurement of that criterion is less than a perfect estimate of true parameters. Self-report measures are often validated by comparing them with behavioral measures of the dimension of interest. This procedure is only justifiable insofar as the behavioral measure represents an accurate estimate of population parameters. Three studies, dealing with the assessment of assertiveness, students’ in-class verbal and nonverbal behaviors, and a number of teacher-student in-class interactions, tested the adequacy of behavioral versus self-report measures as accurate estimates of behavioral parameters. In Studies 2 and 3 self-reports were found to be as good as behavioral measures as estimates of behavioral parameters, while Study 1 found self-reports to be significantly superior.