Score differencing is one of the six categories of statistical methods used to detect test fraud (Wollack & Schoenig, 2018) and involves the testing of the null hypothesis that the performance of an examinee is similar over two item sets versus the alternative hypothesis that the performance is better on one of the item sets. We suggest, to perform score differencing, the use of the posterior probability of better performance on one item set compared to another. In a simulation study, the suggested approach performs satisfactory compared to several existing approaches for score differencing. A real data example demonstrates how the suggested approach may be effective in detecting fraudulent examinees. The results in this article call for more attention to the use of posterior probabilities, and Bayesian approaches in general, in investigations of test fraud.

分数差异是用于检测考试欺诈的六种统计方法之一（Wollack＆Schoenig，2018），涉及零假设的检验，即在两个项目集上考生的表现相似，而替代假设是在其中一项上比较好。我们建议，为了进行评分差异，应使用一项相对于另一项性能更好的后验概率。在模拟研究中，与几种现有的分数差异方法相比，建议的方法表现令人满意。一个真实的数据示例说明了所建议的方法如何有效地检测出欺诈性考生。本文中的结果呼吁人们更多地注意后验概率的使用，并且通常采用贝叶斯方法，