A conceptual model, proposed by Brunswik (1955), that shows how an expert receives feedback in a situation. The model is related to judgmental bootstrapping and econometric methods, as shown  here.


The X’s are causal variables. The solid lines represent relationships. The bs represent estimated relationships according to the actual data, while the s represent relationships as seen by the judge. The dashed line represents feedback on the accuracy of the judge’s predictions. The judgmental bootstrapping model can provide feedback to the judge on how she is making forecasts. The econometric model provides information on the actual relationships. Actual outcomes and a record of forecasts are needed to assess accuracy. Given that the econometric model provides better estimates of relationships, one would expect that such feedback would be the most effective way to improve the accuracy of an expert’s forecasts. Newton (1965), in a study involving the prediction of grade-point averages for 53 students, found that feedback from the econometric model was more effective in improving accuracy than was feedback about accuracy or information from the bootstrapping model. For a further discussion on the use of the lens model in forecasting, see Stewart (2001).