THE PSYCHOLOGY OF LINEAR JUDGMENT MODELS

The ordinary policy capturing paradigm that focuses on cue-judgement r elations is too limited to serve as a basis for a theoretical understa nding of human judgement. To get on, we need a Brunswikian approach wi th a representation of both the task and the judge. Three stable resul ts from studies with linear models are discussed from that perspective . Following Einhorn et al. (1979), the result that linear models usual ly fit judgement data well is explained by reference to the fact that linear models capture an essential feature of human judgement, viz., v icarious functioning. For the result that judges are inconsistent and that inconsistency varies with the predictability of the judgement tas k, the theory of quasi-rationality proposed by Hammond and Brehmer (19 73) is invoked. Finally, it is argued that the wide interindividual di fferences in policies usually found show that the level of analysis is inappropriate. A given level of achievement can be reached by many di fferent combinations of weights, and we should not be surprised to fin d wide interindividual differences at the policy level. We must search for stability at the level of achievement and those aspects that affe ct achievement, rather than at the level of cue utilisation coefficien ts.