Further, for any operational test, a huge volume of past data is available, and for any item appearing in a present test, there is a high chance that a number of similar items have appeared on past operational administrations of the test. Therefore, ideally, it will be possible to use that past information as a prior distribution in a Bayesian DIF analysis. This paper discusses how to perform such an analysis. The suggested Bayesian DIF analysis method is shown to be an improvement over the existing methods in a realistic simulation study.
