Plagiarism in Student Papers: Prevalence Estimates Using Special Techniques for Sensitive Questions

This article evaluates three different questioning techniques for measuring the prevalence of plagiarism in student papers: the randomized response technique (RRT), the item count technique (ICT), and the crosswise model (CM). In three independent experimental surveys with Swiss and German university students as subjects (two web surveys and a survey using paperand- pencil questionnaires in a classroom setting), each of the three techniques is compared to direct questioning and evaluated based on the “more-is-better” assumption. According to our results the RRTand the ICT failed to reduce social desirability bias in self-reports of plagiarism. In contrast, the CM was more successful in eliciting a significantly higher rate of reported sensitive behavior than direct questioning. One reason for the success of the CM, we believe, is that it overcomes the “self-protective no” bias known from the RRT (and which may also be a potential problem in the ICT).We find rates of up to 22 percent of students who declared that they ever intentionally adopted a passage from someone else’s work without citing it. Severe plagiarism such as handing in someone else’s paper as one’s own, however, seems to be less frequent with rates of about 1 to 2 percent.