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).