Bayesian methods for calibration of examiners

In large public examinations many examiners are required to mark the scripts. These examiners are to be calibrated by requiring them all to mark a sample of common scripts. Paul (1979) used an additive model and a linear relationship model to describe the examiners' behaviour in marking the scripts, and gave estimates of the parameters from a sampling theoretic approach. In this paper Bayesian estimates of the parameters of the models are given. Real examination data and simulated data are analysed and the conclusion of Paul (1979) that there is very little to choose between the models is confirmed. It seems that the additive model is adequate.