The correct model is probably (estimated test score + estimation noise) = (actual test score + test noise). The test contains a random element, e.g. guessing, t

The correct model is probably (estimated test score + estimation noise) = (actual test score + test noise). The test contains a random element, e.g. guessing, that the person can't estimate. https://en.m.wikipedia.org/wiki/Regression_dilution https://en.m.wikipedia.org/wiki/Regression_dilution https://en.m.wikipedia.org/wiki/Errors-in-variables_models https://en.m.wikipedia.org/wiki/Errors-in-variables_models