This article extends the work by Armstrong and Shi on CUmulative SUM (CUSUM) person-fit methodology. The authors present new theoretical considerations concerning the use of CUSUM person-fit statistics based on likelihood ratios for the purpose of detecting cheating and random guessing by individual test takers. According to the Neyman-Pearson…

Students write papers in many of their courses to improve their writing skills and to foster an active attitude toward learning. Every year, they hand in hundreds of papers for teachers to assess. This stream may get polluted in two ways: by simple copying from Internet sources and by the exchange of text fragments between students. These…