This study investigated statistical properties of the K-index (Holland, 1996) that can be used to detect copying behavior on tests. A simulation study was conducted to investigate the applicability of the K-index for small, medium, and large datasets. In addition, the Type I error rate and the detection rate of this index were compared with the…

A statistical test for the detection of answer copying on multiple-choice tests is presented. The test is based on the idea that answers of examinees to test items may be the results of three possible processes: (1) knowing; (2) guessing; and (3) copying. Examinees who do not have access to the answers of other examinees can arrive at their…

A statistical test for detecting answer copying on multiple-choice tests based on Cohen's kappa is proposed. The test is free of any assumptions on the response processes of the examinees suspected of copying and having served as the source, except for the usual assumption that these processes are probabilistic. Because the asymptotic null and…

Two new indices to detect answer copying on a multiple-choice test, S(1) and S(2) (subscripts), are proposed. The S(1) index is similar to the K-index (P. Holland, 1996) and the K-overscore(2), (K2) index (L. Sotaridona and R. Meijer, in press), but the distribution of the number of matching incorrect answers of the source (examinee s) and the…