# How to deal with students copying?

In university courses with compulsory homework, I quite often find students copying their work from others. Now, you can simply ignore this since they are responsible for their learning. If not, usually a very annoying game starts, where students try to slightly modify their soultions and teachers become detectives. I am not sure if this is helpful.

Is there any literature or best practice experience on the problem of how to deal with copying of mathematics students?

• There is maybe a case where the game does not start: If you have homework where students have to write some code (e.g., in numerics this is often the case that some algorithm have to be implemented), then you can use plagiarism software (e.g. theory.stanford.edu/~aiken/moss). The software analysizes the structure and ignores empty lines or renaming of variables. If a student can trick the software, he has almost done the same work as someone actually doing the exercise. However, your question have to be difficult and long enough. – Markus Klein Mar 18 '14 at 7:43
• No literature, just personal anecdote: I had to grade homework questions where in the end only a certain threshold needed to be met (no marks, just pass/fail). My mode of grading work where the one student copied another one was awarding half the points with the remark "Same answers as XXX. Half the work, half the points." To my judgement, the message was recieved. For written homework (not code), I think that, if the students manage to obfuscade the fact that they copied, they put in some effort to understand what's to be done. – Roland Mar 18 '14 at 11:04
• @Roland, I used to grade like that. In addition, I would also give the one who was copied from half the points. In effect, there was only one work, and two people claimed it, so half the points go to each. – Joel Reyes Noche Mar 18 '14 at 13:47
• @JoelReyesNoche Oh, yes, indeed. My notion of copying is transitive. Both parties with the same answer are getting half the points; I remember awarding one third of the points on three different homeworks. – Roland Mar 18 '14 at 17:40
• What I do is to "randomly" select a (small) sample of students for each homework, which then have to explain what they turned in. The grade of the oral is then the grade of the homework. The rationale is that I really don't care if they copied/worked together/found the answer on the 'web, I care that they understand the subject matter. – vonbrand Mar 18 '14 at 21:00

At my university the focus is moved to tests and exams. In larger courses homework has usually no or very little significance, while in smaller classes very few attempt copying (it is too easy to spot).

On the other hand, programming homework is handled via plagiarism software (we have our own, its internals being kept secret; the output is reviewed manually), this is a routine procedure, as homework is usually tested automatically, and it is a standard step in various national-level contests that our university handles.

Now, to answer your question, how to handle copying when it happens? I know of three ways:

• By a formal process. The statute of our university says it's forbidden to do so (I suspect this is not unique), and such a student could be expelled. In practice, as far as I can remember, it had never happened. I heard that there had been such attempt, however, the student council had caused enough trouble that it all had come to nothing. This might have something to do with the fact, that the STEM-campus and the humanities don't like each other very much and the student council is in majority from the latter.
• Fail the course. Some insist that such students shouldn't be allowed to attend the make-up session exam, but this would result in a bureaucratic mess. Instead, by plagiarism the student achieves an equivalent of $-\infty$ points and it all fits into professor's "freedom of grading".
• By some agreement. This might be not the most fair, but during their first semester, it might be the most appropriate. Students come from various neighborhoods, their high-school had different policies and are frequently immature. A good talking-to has more positive effects than punishment, which you could still apply later if he/she hasn't learned from the mistakes. Fortunately, at my university copying is rare enough that we can afford such a lenient treatment (and you don't even need to keep track, because people remember).

I hope this helps $\ddot\smile$

• "So, professor, how will this -$\infty$ average into my grade?" – Andrew Jan 22 '16 at 13:54
• @Andrew Professor: "Your grade on the exam was 6/10. So your total grade is (winking while writing it down) $-\infty\cdot w+ 6/10\cdot (1-w), \;0<w<1$. If you can tell me "how much that is" I will give you a passing grade." – Alecos Papadopoulos Jan 22 '16 at 15:24