FIGURE 1.

Numerical information of the Skiwell Manufacturing Company task. (A) Information provided in percentages. Hit rate and false-alarm rate have been normalized with respect to the base rates of the two suppliers. (B) Natural frequencies with suppliers at the intermediate level. The frequencies of the four conjunctive events implicitly contain the base rate information about the suppliers. (C) Natural frequencies with diagnostic information at the intermediate level. From the perspective of (B), the tree in (C) represents a Bayesian update, in which the four distinct events are now conditioned on diagnostic information.