(PhysOrg.com) -- A 15-minute Web-based tutorial that teaches students what constitutes plagiarism and how to avoid it reduces cases of plagiarism by 65 percent, a new study shows.

A follow-up survey of participating students suggests that the intervention reduced by expanding their knowledge of writing strategies and this type of cheating, rather than by increasing the perceived probabilities of detection and punishment.

The study by Brian Jacob, a professor at the University of Michigan Gerald R. Ford School of Public Policy, and Thomas Dee, an economics professor at Swarthmore College, examined the prevalence and predictors of plagiarism among college students.

Student surveys suggest that plagiarism is common in higher education. Many observers argue that rapid technological advances—such as access to full-text resources and cut-and-paste word processing—have dramatically increased plagiarism on college campuses. Until this study, however, there has been little data on the prevalence or determinants of this illicit behavior.

The study involved 28 undergraduate social science and humanities classes at a post-secondary institution. In total, the researchers collected more than 1,200 papers from 573 college students during the fall 2007 semester. These students were not aware that they were participating in the study, but were required by their instructors (who knew about the study) to submit writing assignments electronically through Blackboard-based course web sites.

Students in half of the courses were required to complete an anti-plagiarism tutorial before submitting their papers. The tutorial required students to read through 18 screens that defined different forms of plagiarism, and outlined effective strategies for avoiding plagiarism such as not procrastinating and careful note-taking. Students then completed a nine-question quiz that allowed each response to receive detailed feedback on why that answer was correct or incorrect.

At the end of the semester, researchers analyzed each paper for plagiarism using a proprietary plagiarism-detection software (Turnitin.com). Plagiarism was largely concentrated among males and students with lower SAT scores, the researchers said.

Research also showed that the assignment to the treatment group substantially reduced the likelihood of plagiarism, especially among students with low SAT scores.

Plagiarism, which involved using sentences or sentence clauses without attribution, occurred in 3.3 percent of the papers from courses randomly assigned to the control condition. The web tutorial reduced instances of plagiarism by roughly two percentage points, a reduction of nearly two-thirds.

A follow-up survey of participating suggests that the intervention reduced plagiarism by increasing student knowledge rather than by increasing the perceived probabilities of detection and punishment.

The study, "Rational Ignorance in Education: A Field Experiment in Student Plagiarism," was published online by the National Bureau of Economic Research.

More information: www.nber.org/papers/w15672