A Conceptualization of the Multitude of Strategies in Base-Rate Problems

Abstract

Although the need for an investigation of the individual’s cognitive strategies has repeatedly been formulated (cf. PAYNE, BRAUNSTEIN, & CARROLL, 1978; SCHOLZ, 1981; PHILLIPS, 1983, or the critique presented in Chapter 2.3. above; positive exceptions being MONTGOMERY & SVENSON, 1983; HUBER, 1983; ALLWOOD & MONTGOMERY, 1981, 1982), very little research has been undertaken until now that may be regarded as process studies in probability judgments. The cascade of questions in the concluding section of the last chapter provides a rather broad scope of starting points for an investigation of the judgmental process. Therefore, there is a need to more closely specify the focus of this chapter. There are two issues that will be dealt with in some detail. First, up until the present time, hardly any knowledge has been acquired about “which comprehension of text and questions subjects have at the base-rate fallacy” (SCHOLZ, 1983a). The subjects’ problem understanding should be the first step in any process study as has already been emphasized in early work on problem solving (cf. SELZ, 1913, 1922). Hence we will begin with an analysis of written reproductions of the question on the requested conditional probability and will introduce a classification of the possible meanings which may be attributed to the question by subjects. Second, the judgmental process itself will be investigated by means of an analysis of written protocols.