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The Development of Statistical Indices for Detecting Cheaters

Angoff, William H.
Publication Year:
Report Number:
ETS Research Bulletin
Document Type:
Page Count:
Subject/Key Words:
College Board, Cheating, College Bound Students, College Entrance Examinations, Evaluation Methods, Measurement Techniques, SAT


Comparison data on SAT verbal and mathematical were collected on pairs of examinees in three samples for later use in detecting instances of willful copying. Two of the samples were constructed with the knowledge that no examinee could possibly have copied from the answer sheet of any other examinee in the sample. The third sample was taken entirely from a single center believed to be free of cheating. In each sample the answer sheet of each examinee was compared with the answer sheet of every other examinee. Eight detection indices were developed and distributions were run for possible operational use in making future judgments regarding examinees who were actually suspected of copying. Covariance analyses between samples indicated statistical but not practical significance, and consequently it was judged that any one of the samples could serve the purposes of operational detection as well as either of the other two. Empirical tryout of the indices against known and admitted copiers gave some results which permitted the elimination of three of the indices from further use. Practical considerations removed a fourth, and further statistical study eliminated two others. The remaining two have been in successful operational use at Educational Testing Service for more than two years. (Author) (25pp.)

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