Social Judgement Theory (SJT) evolved from Egon Brunswik's Probabilistic Functionalist psychology coupled with multiple correlation and regression-based statistical analysis. Through its representational device, the Lens Model, SJT has become a widely used, systems-oriented perspective for analysing human judgement in specific ecological circumstances. Judgements are assumed to result from the integration of different cues or sources of perceptual information from the environment. Special advantages accrue to the SJT approach when criterion values (or correct values) for judgement are also available, as this (...) permits the comparison of judgement processes to environmental processes and leads naturally to the generation of cognitive feedback as an aid to facilitate learning. In contrast to more prescriptive approaches to decision analysis, the SJT approach analyses judgements by decomposing the judgement process after judgements have been rendered. This a posteriori decomposition is accomplished by first using multiple regression analysis to recover prediction equations for both the judgement and ecological systems and then using the Lens Model Equation to compare those systems. SJT methods maintain close contact with ecological circumstances by employing the principle of representative design (which focuses on how the researcher obtains the stimuli for judgement) and avoiding unwarranted over-generalisations from nomothetic aggregation (e.g. averaging across judges) through the use of idiographic statistical analysis. SJT methods have proven valuable in the analysis of individual judgements as well as groupbased judgements where conflict becomes likely. (shrink)

As Hammond has argued, traditional explanations for disagreement among experts (incompetence, venality, and ideology) are inadequate. The character and fallibilities of the human judgement process itself lead to persistent disagreements even among competent, honest, and disinterested experts. Social Judgement Theory provides powerful methods for analysing such judgementally based disagreements when the experts' judgement processes can be represented by additive models involving the same cues. However, the validity and usefulness of such representations depend on several conditions: (a) experts must agree on (...) a problem definition, (b) experts must have access to the same information, and (c) experts must use the same organising principles. When these conditions are not met, methods for diagnosing and treating disagreement are poorly understood. As a start towards developing such an understanding, sources of expert disagreement are discussed and categorised. (shrink)

There is sufficient evidence from more recent experiments in psychology that equal retinal stimulus-elements do not lead to equal experiences and reactions except under certain rather specific conditions. An unsophisticated observer will find himself surprised to be able to cover with his own finger a person entering the door of his living room. When the finger is moved to the right or left, thus doing away with the precise retinal coincidence with the person, the observer will soon become unable to (...) recognize intuitively the actual retinal stimulus equality of the two distant things. This usually holds even for the case when he is making every inner effort towards an antagonistic, analytic perceptual attitude of the type which is used by painters or draughtsmen in order to represent the environmental situation in a similar way as it would project itself on a photographic plate or on a retina. (shrink)