Will tutorials prevent student plagiarism?

There is a report on a 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 suggesting that a short tutorial on plagiarism can reduce plagiarism in writing assignments by around 2/3. It's a bit hard to believe.

The sample set was from 28 undergraduate social science and humanities classes and involved more than 1,200 papers. Among students not receiving a tutorial on plagiarism unattributed copying was stated to have occurred in 3.3 percent of the papers,
which seems remarkably low, even when compared to events during the Routman "Semester at Sea" adventure. The 3.3% number was stated to drop by 65% with a tutorial about plagiarism. One wonders if the tutorial might have been a signal to the students, who responded to the signal, not to the content, of the tutorial? Economics "research" in action?

The study found plagiarism to be largely concentrated among males and students with lower SAT scores. Does this relate to the incident of Joe Biden at Syracuse Law School?

Blackboard-based course web sites were used. See
http://ipbiz.blogspot.com/2009/07/blackboard-whacked-by-cafc.html