Detecting test fraud using Bayes factors

According to Wollack and Schoenig (Cheating, in: Frey BB (ed) The SAGE encyclopedia of educational research, measurement, and evaluation, Sage, Thousand Oaks, pp 260–265, 2018), score differencing is one of six types of statistical methods used to detect test fraud. In this paper, we suggest the use of Bayes factors (e.g., Kass and Raftery in J Am Stat Assoc 90:773–795, 1995) for score differencing. A simulation study shows that the suggested approach performs slightly better than an existing frequentist approach. We demonstrate the usefulness of the suggested approach using a real data set that involves actual test fraud.