• Former postdoctoral fellow Young-Jin Lee, left, and David E. Pritchard, the Cecil and Ida Green Professor of Physics

    Former postdoctoral fellow Young-Jin Lee, left, and David E. Pritchard, the Cecil and Ida Green Professor of Physics

    Full Screen

Homework copying can turn As into Cs, Bs into Ds

MIT physics educators investigate a bad habit’s perils — and demonstrate a solution.

Press Contact

Jen Hirsch
Email: newsoffice@mit.edu
Phone: 617-253-2700
MIT News Office

Media Resources

2 images for download

Access Media

Media can only be downloaded from the desktop version of this website.

Copying a few answers from another student’s math or science homework assignment occurs much more frequently than copying during examinations or plagiarism on term papers. It is rarely prosecuted by discipline committees and is regarded by many American college students as either not cheating at all or simply a minor infraction. Now educators at MIT have shown that homework copying is associated with greatly decreased learning — and have developed changes in instructional format that reduced copying by a factor of four in certain physics classes at MIT.

This research was conducted by the Research in Learning, Assessment, and Tutoring Effectively (RELATE) program headed by David E. Pritchard, the Cecil and Ida Green Professor of Physics. By analyzing records of student submissions to Mastering Physics, an online homework and tutorial system, a team led by graduate student David Palazzo developed algorithms to detect copied answers based on earlier work led by Postdoctoral Fellow Rasil Warnakulasooriya. Postdoctoral Fellow Young-Jin Lee also contributed to the research, published today online in Physical Review Special Topics: Physics Education Research.

The group investigated the effect of homework copying on students’ performance. It found that the copying of problems that require algebraic responses correlated with two letter grades’ worse performance on problems demanding similar responses on a final exam (but found that copying did not adversely affect grades on conceptual questions). This decline caused repetitive copiers — students who copy over 30 percent of their homework problems — to have over three times the failure rate of the rest of the students in spite of their starting the semester with equal ability in math and physics.

According to Lee, now assistant professor of educational technology at the University of Kansas, “The decrease of copiers’ relative performance over the semester is as strong as anything in the education literature. Since the copiers do learn physics topics on which they don’t copy the homework, it strongly implies that copying caused their declining relative performance on the algebraic problems later in the semester.”

Tracking a bad habit

The copying showed surprisingly strong temporal patterns. Students who copied little or none of their homework had completed about half of their weekly assignment two nights before it was due, whereas repetitive copiers had done only about 15 percent. More dramatically, the rate of copying increased notably over the semester and was three times higher after midterm exams than during the first three weeks of the semester. “It took them about three weeks to establish their networks,” said Palazzo, now a professor at the U.S. Military Academy.

Homework copying was detected based on the elapsed time between when a student opened the problem in his browser and the time when he had correctly submitted all the answers. When the elapsed time was too short for the average student to read the problem and enter the several required answers, the problem was regarded as having been copied.

By measuring actual copying, this work provides a checkpoint for the large body of work on academic dishonesty based on anonymous surveys of students. The actually observed rate was about 50 percent higher than on a similar anonymous survey given to the MIT students. In addition, survey data combined with actual copying patterns confirmed three demographic indicators found in previous self-reported work: men copied significantly more than women, business majors copied much more than either scientists or engineers, and those most interested in obtaining a grade copied more than those most interested in obtaining an education. In addition, it appears that students interested merely in obtaining a passing grade delay starting serious work and resort to copying under pressure of the deadline.

In surveys, students nationally report both more academic dishonesty and more moral tolerance for it than do students at MIT. “It’s hard to escape the conclusion that homework copying is an even worse problem nationally than in the worst semester we studied at MIT,” said Palazzo. The surveys also reveal that more copying is reported for written than for online homework; at MIT, students reported nearly twice as much copying of written homework as of online homework.

A remedy for copying

The MIT group observed the overall copy rate decline by a factor of four over three years as changes were made to the instructional format. The largest reduction of copying occurred when Physics I: Classical Mechanics (8.01) was changed from a lecture-recitation format to the more intimate technology-enabled active learning (TEAL) format, which features more personal contact with teachers and teaching assistants (and a student-to-staff ratio below 20). A further factor of two reduction occurred in Physics II: Electricity and Magnetism (8.02) when the interface in the course’s tutoring program was changed to make copying more difficult and the grading system changed from pass/no record to A, B, C/no record.

Pritchard concludes from his research that copying written homework is a serious cause of course failure nationally, especially in large lecture-recitation courses. “We came upon homework copying through our research on learning in an online environment, rather than through moral concern,” Pritchard says. “But our results are so strong that they place a moral imperative on teachers to confront homework copying and to reduce it. Fortunately, we found some changes that dramatically reduce copying without turning teachers into policemen.”

Topics: Education, teaching, academics, Faculty, Students


While it may appear that 30 questions answered in 2 minutes is indicative of cheating, it's important to consider students who do all of the work on paper and then enter the answers when they're all done. Many students do this, students who don't like to constantly be staring at a computer screen while doing physics.

I understood that MIT encourages students to work together in teams to complete homework problems. If this is so, does not this procedure conflict with the findings of the study? It would seem that MIT should encourage each student to work alone on homework problems.

In the engineering sciences it's often the case that problems can be parameterized. I would imagine in this age of tech that if each (or at least most) homework problem(s) had specific parameters incorporated into the problem on a per student basis, copying would be drastically cut. In other words, each homework assignment would have a unique id and be a minor variation on the others. And I concur with snively in that I work out problems on paper before entering them online.

I find it interesting that the article is so focused on "copying". Isn't the root cause of the poor performance the fact that the students are not doing the work? The copying is only a symptom for students who feel the need to turn in their homework but can't bring themselves (for whatever reason) to do it.

Since the root cause is students not doing the work, it seems that we should be addressing the issue of how to get students to "do the work".

Or perhaps we should let the students sort themselves out based on who is willing to put in the effort (or find the necessary resources to help them understand how to do the work).

To snively's point - are you suggesting that it might be the case that doing all the work on paper and then entering the answers would be correlated with poor performance on tests?

To the extent that people who are not copying are categorized as "copiers" it is only diluting the evidence for the hypothesis.

My conclusion - actually doing the homework is the best way to ensure success on the test (especially in problem set oriented classes). It was true when I was in school 30 years ago and it still seems to be true!

As an undergraduate at MIT many years ago, I did all my homework on my own (no copying, no help from others, no help to others). I was quite successful (grade-wise), so I had no reason to question this method.

When I got to graduate school (13 person PhD program), about 7 of us would routinely work on problem sets in a large group. I found this to be enormously more productive for everyone involved than working on our own.

For the higher performers, they benefited from teaching other. For the lower performers, they benefited from the assistance of others.

The only risk is that someone would simply sit and listen and "get the answers" without putting in any thought. This was mitigated by the fact that everyone wrote up their own problem sets. So, we weren't copying, we were, as a group, discussing approaches, finding counterexamples, etc.

Based on this quote from the article, "It found that the copying of problems that require algebraic responses correlated with two letter grades’ worse performance on problems demanding similar responses on a final exam (but found that copying did not adversely affect grades on conceptual questions)."

we were getting the best of both worlds.

By writing up the problem sets on our own, we would get the benefit of "doing the algebra" while working out the concepts together.

In my opinion, this approach should be encouraged more often.

The issue MIT should be focused on is whether students are learning in the best, most effective way they can. Instead of putting attention on anti-cheating, if would be better to focus on making positive changes, like teaching students time management skills and that learning is more important than a grade.

Here's the scenario.. You're a student. You have an hour to turn in your homework and still have no idea how to do it. Part of your grade is based on homework. Getting a bad grade would upset you, disappoint your parents, make a company less likely to hire you, and ultimately make you less of an intelligent, valuable human being.

The issues within that scenario should be addressed. Improving time management skills, helping students admit that they need help earlier in the process (very difficult for many MIT students), and teaching students that a grade is just a letter and a bad one does not diminish you as a human. Teaching students that the real power is in learning and being true to one's own purpose and sense of personal integrity.

Back to the top