ABSTRACT

We have stressed the fundamental unity between the experimenter’s activities and those of the assessor and therapist, but there is a critical difference between them. In experiments it is the experimenter who thinks about what he wants to study; he selects and defines his independent variable and the dependent measures for assessing the effects of his treatment manipulations. He may begin with more interest in the dependent variable—for example, self-control or aggression—and inquire into the effects of various manipulations on it. Or he can start by focusing on the independent variable, say the effects of exposure to particular influence procedures. The experimenter must select for measurement and manipulation events that represent those in which he is interested and with which he claims to be concerned. The operations for specifying the exact content and measurement of the variables in the experiment are assessments and they entail many of the same steps and problems involved in the clinical assessment of the individual case.