Additive Integration of Information in Multiple-Cue Judgment

Sammanfattning: This thesis investigates adaptive shifts between different cognitive processes in multiple-cue judgment tasks. At least two qualitatively and quantitatively different cognitive strategies can be identified: one process in which abstraction and integration of cue-criterion relations form the basis for the judgment (Einhorn, Kleinmutz & Kleinmutz, 1979) and one which is based onsimilarity comparisons between a probe and similar exemplars stored in memory (Medin & Schaffer, 1978; Nosofsky, 1984; Nosofsky & Johanssen, 2000). Within the framework of a proposed model of judgment, Σ, these processes are regarded as complementary means to deal with a proposed capacity limitation of our cognitive architecture; in situations of unaidedabstraction and integration of information we are forced to handle pieces of information in an additive and linear manner. Predictions by Σ concern which of the two processes that will dominate judgments in different judgment tasks. In a judgment task where the underlying combination rule is additive and linear we are able to abstract and integrate information on how cues relate to a criterion and produce judgments that are consistent with the combination rule. In a judgment task where the underlying combination rule is multiplicative we are not able to abstract and integrate this information, and we are therefore induced to use a strategy of exemplar memory. Two studies test these predictions. In Study 1 the results confirm that in an additive judgment task cue abstraction was induced, while exemplar memory was induced in amultiplicative task. These results were replicated in Study 2, where a more complex judgment task was used. The results reported in this thesis provide tentative support for the idea of an adaptive division of labor between cue abstraction and exemplar memory as a function of the task, an ability we are equipped with to cope with a cognitive architecture only allowingelaboration of information in an additive and linear manner.