Resources for Preventing and Detecting Plagiarism

This page is an informal collection of Web resources on preventing and detecting plagiarism. If you discover more useful resources, please pass them along to me at

Preventing Plagiarism

"Thinking and Talking about Plagiarism." A Bedford/St. Martin's teaching tip with excellent information on talking to students about plagiarism and individual policies on plagiarism.

"Preventing Academic Dishonesty," adapted from Barbara Gross Davis, Tools for Teaching. This provides good strategies for preventing plagiarism of all sorts, including papers and blue book exams.

"Anti-Plagiarism Strategies for Research Papers," by Robert Harris. This site provides good all-around advice for preventing and detecting plagiarism

All of these sites stress plagiarism detection. Although some deal with detecting plagiarism, few go into detail about two of the most useful plagiarism detection services.


Detecting Plagiarism This is free plagiarism detection service. Instructors register and receive an instructor code. Then instructors can paste student papers into a text box and within twelve hours (advertised turnaround time; the actual turnaround time can be much longer) sends an email message and posts a report. The service searches the Web, including cheat and personal sites, and it also searches its own database of papers. The service stores a copy of the paper in a database for future searches; this helps to detect students who submit papers that have been previously submitted. It does not distribute entries in the database. This is a pay service very similar to Instructors get an instructor ID, and they can submit electronic copies of papers. Then the service generates a report. It searches the Web, including cheat sites. Like, the service stores papers in a database and searches its database, but it does not distribute database entries. One feature that this site offers is that students can submit papers directly to the service, having the report automatically sent to the instructor. This is a useful feature, for instructors can require students to submit papers to the site as a requirement of the course, and it saves the instructor the time of having to submit them him/herself. is a good option for individual instructors. It is free, and is especially useful for instructors who suspect plagiarism and want to find a source. It povides a detailed report with two windows, one with the student text, complete with hyperlinks to the bottom window, which provides the submitted text and the text from the online source. advertises itself as a complete plagiarism prevention and detection service. Individual, departmental, and institutional licenses are available, and it also advertises a peer review service to help students evaluate each other's work. The report differs slightly from, but provides most of the same information. This one's especially good if you want everyone to submit reports prior to submitting essays.

I have had almost identical results with these services. Both generate reports that list the percent possibility that an essay has been plagiarized, and both generate detailed reports, offering the ability to compare student text with potential sources via a color-coded report with hyperlinks to possible sources. Better yet, both sites can detect patchwritten papers--papers that come from a source but whose language students have changed.

You need to be careful, though. Neither of these services recognize quotation marks. So an report might come back saying that the essay was 20% plagiarized, when all of the flagged material are quotations.

Strategies for Preventing Plagiarism

Clear Explanations

Instructors need to explain everything very clearly to students. If we hope to prevent plagiarism, we need to make students know the difference between mismanagement of sources (like failure to cite or quote) and plagiarism (cheating). This is probably best handled in conversations throughout the term. Instructors should stress the importance of citing sources and the damage that plagiarism does to the academic development of the plagiarist and to the academic environment.

Instructors should also clearly explain their plagiarism and cheating policies, stating specific punishments for cheating and, just as important, sticking to those policies.

This is, of course, a punitive approach, but explanations also facilitate a purely preventative approach. Explain assignments and grading criteria clearly. Students will then know not only information about plagiarism but also how to better avoid it.

Assignment Design

Pay special attention to how you design your assignments. Broad topics that require a term paper (that is, a paper that is submitted at the very end of the term) invite students to search for papers online. It's pretty easy to find a paper on Hamlet, for instance. Narrowly-defined topics make chances slim that papers are available on that topic. An assignment that asks students to compare Hamlet is better than a broad paper "on Hamlet" because this type of assignment limits the number of papers that will be available online.

The best way to do this is to establish a specific set of topics for any course--say two dozen--and to make students choose one from those topics. Changing the assignments each time a course is taught will help to eliminate repeat submissions.

Another strategy related to assignment design is instructor management of sources. If instructors specify sources, students will find it more difficult to cheat. You can provide the exact sources that students can use, or you can require a particular set of sources: say an interview, two sources from a specific journal, two books, and perhaps a data set that you provide. For a hypothetical paper on Hamlet, I might provide all of the sources to be used on Blackboard. Or I might require that students use no Internet sources and at least four sources from Shakespeare Studies. Similarly, requiring that all sources be recent--say from the last five years--helps to eliminate the chance that students will submit plagiarized papers, since most papers available online are dated.

Focus on Process

Another way to prevent plagiarism is to focus on process over product. Granted, the primary part of the grade will probably come from a final product. However, there are some process-focused techniques that can greatly reduce the temptation that students might feel to plagiarize. These include:

Just the act of collecting a draft--early in the term--will deter plagiarism, for it requires students to engage in the writing and research process early, and research has shown that one of the primary reasons that students plagiarize is procrastination. As the deadline approaches, the chances of succumbing to temptation increase.


Having students present their papers orally to the class is another good method of preventing plagiarism, especially if they know that you or the class will ask questions. The act of presenting a topic to the class means that students must be prepared and understand their written work; plagiarists rarely have a complete understanding of what appears in their plagiarized papers.

Strategies for Detection

There are some tell-tale signs that a paper has been plagiarized. These include:

Run essays that display any of these features through one of the plagiarism detection services listed above.

Strategies for Confronting Students

Confronting students whom you belive have plagiarized is probably the most uncomfortable part of the plagiarism issue. A charge of plagiarism is serious. If you're convinced that a student has plagiarized, confront the student directly. An email or phone call where you tell the student that you want to discuss his/her paper will do the trick, then speak in person.

Typically, a discussion of the paper will get the student to confess. You might ask the student to explain a concept that appears in the essay. Usually, a student who has plagiarized will stumble around an explanation, and often will confess to having relied on a source for the information.

If the essay reveals mixed citation styles, no references, missing references, strange formatting, and shifts in style, you could ask the student why these occur in the essay. If the essay is stylistically above everything that the student has done previously, you might ask about the process of writing and revision, probing the student for information on how he/she improved his/her writing in such a short time.

Questioning the student will often prompt the student to confess. But what if it doesn't? Then you have a choice to make. If you still believe that the student plagiarized, you'll need to gather your evidence and be able to present it to the student in the meeting, as well as to the university. If you have found the source, this is simple. Once you've questioned the student (or even without questioning him/her), you can reveal that you have found the source.

What you decide to do at this point is up to you. Research has shown that faculty are reluctant to pursue plagiarism cases, believing that it is best handled between the student and the instructor. My personal opinion on this is that faculty need to stick to their plagiarism policies. If the policy says that the student will fail the course, then faculty need to follow this up with action. Students talk, and not adhering to a policy is a sure way to attract potential plagiarists to your sections.

Charges of Plagiarism

Bringing a charge of plagiarism is a serious and detailed task. I follow the following procedure for charging students with plagiarism.

  1. I gather the evidence that I have. I typically make sure that I can find the plagiarized sources, and then I make 4-5 copies of them: one for me, and one for the Chair, Dean, and any others who will need to be involved. I also copy the plagiarized paper as submitted, and I highlight plagiarized sections. If I have a report from a plagiarism detection service, I copy that, as well.
  2. I then draft a letter officially charging the student with plagiarism and detailing the action that I am taking and the action that I want the institution to take. It's helpful to quote your plagiarism policy and the institution's policy, as well. In this letter, I refer to the copies that I have made to illustrate the severity of the case. It is essential to include the assignment, the date the student submitted the assignment, and the approximate date that you began investigating plagiarism.
  3. Package all of the materials into envelopes, include a copy of your letter, and send them to your Chair, your dean, the dean of the student, and anyone else who might get involved. At my institution that means the registrar, since he starts an academic dishonesty file on the student. Make sure that you keep one set of materials for yourself in case there are questions.

I make sure that there is no doubt when I issue a charge of plagiarism because, as I've said, it's a serious issue for both the student, you, and the institution. For that reason, I have never charged a student with plagiarism unless I have found the plagiarized source, and I have--to my knowledge--never had a student challenge the charge.