This essay is excepted from Gary K. Clabaugh & Edward G. Rozycki, Preventing Cheating and Plagiarism, 2nd Edition pdf. (2009) Oreland, PA: NewFoundations Press.

Deterring, Detecting and Tracing Plagiarism

edited 2/16/12

Discouraging and detecting plagiarism is an unpleasant business. Instructors don't want their classroom to turn into a security state. But at the same time they know that, given half a chance, some students will not be honest. And they certainly don't want principled students doing the work, while their unprincipled classmates steal the same grade. What is to be done?

Deterring Plagiarism

Let's begin by considering the student perspective. For them things can seem a bit confusing. Disciplines require different types of citation. What one discipline considers "common knowledge" another does not. What one instructor requires, another waives. What one prefers, another abhors. Such variations, particularly when coupled with misunderstandings and inexperience, can lead to actions that look like plagiarism, yet are quite innocent.

With this caution in mind, here are some tested methods for deterring plagiarism.

General Procedures

Preventing plagiarism is clearly preferable to having to deal with it after it happens. Here are some general procedures that deter plagiarism.

Make sure students know what counts as plagiarism in your class. (The Plagiarism Book helps with that.)

Indicate in writing the penalties you are prepared to assess for plagiarism. But make sure you don't go out on a limb that might get sawed off.

Note:     Before pre-announcing penalties, consider that unknown consequences offer a different kind of deterrence: "uncertainty avoidance."

Imagine that students maintain files of your past tests and take the necessary precautions.

Enforce the same due dates in multi-section courses and be wary of granting extensions. James Brown ( reports that one of his students repeatedly asked for deadline extensions. The reason? He was secretly waiting for a friend who had a different instructor in another section of the course to get her paper back. Brown's student stalled because he didn't want his plagiarized paper and the original to simultaneously be in the hands of instructors.

Let your students know that you are aware of the cheat sites on the Web. (The Plagiarism Book cautions that you have been provided with detailed information on these sites.) Initially, we worried about acknowledging such sites even existed. But the thousands upon thousands of hits these sites record suggests that students know about them already.

The full text of Preventing Plagiarism and Cheating has been reissued. It can be accessed via this link.

Other topics covered in the whole text are

Assignment Sequence and Design

Here are assignment sequencing and design tips that deter plagiarism.

Have students write an early in class assignment, grade it, and keep it on file. (This provides a baseline to compare with work done out of class and discourages nascent dishonesty.) ...

Referencing Strategies

Referencing strategies can be a significant plagiarism deterrent. Try some of these.

Offer students practical advice on keeping track of their sources while doing research. Because of its volatile nature, this is particularly important to students using the Web. Remind them to ....

Detecting Plagiarism

Here are some of the better detection techniques we gleaned from the web, interviews with educators and personal experience. Some might be obvious to veteran instructors, but not to novices.

Look for ...

Tracing Plagiarism

To nail a plagiarist you often need the original he or she counterfeited. Finding that can be quite a challenge. You might get lucky and remember where you originally saw the work in question. That's happened to us. But it usually isn't that easy. Here, then, are a few tracing strategies. ...

Phony References

Here we're not dealing with plagiarism but something that goes hand-in-hand. Students use inaccurate and concocted references to lend an air of authority or an appearance of substantiality. The trouble is, bad references are often difficult to detect because of the labor involved. Here's a suggestion for dealing with that. ...

The chart below summarizes a procedure by which pre-verified good and bad references are given to students to check out. The instructor can use this as a gradable activity since he or she knows which references are good ones. ...


Few educators enjoy flunking plagiarists or hauling them before disciplinary boards. You often can avoid such unpleasantness with preventative strategies. Those we've just reviewed can be thoughtfully brought together into potent formulations that usually make sanctions unnecessary.