ABSTRACT
Much experimental work in psychology has relied on the objective definition of the situation. Psychological problems have been studied by varying systematically the characteristics of the situation and observing or measuring the variability of the person's reactions. The relationship between the variation in the objective characteristics of the situation and the variation in the person's reaction is used to draw conclusions about the mediating process between input and output. Implicit in this approach is the assumption that persons react on the basis of external stimulation. Therefore one fundamental problem for this approach is to specify and measure the external situation as objectively as possible.
