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When I went to my university to hand in my Maths work (5 questions, worth 25% of the grade for the unit) I met with a friend who told me that somebody had been asking questions from the coursework exactly as asked on this Exchange. Naturally I was curious and I found them:

find x where $x^{11} \mod 41 = 10$

Prove that $n^4−1 $ is divisible by 5 when n is not divisible by 5.


Posted by the same user, all recently. This is no coincidence and the use of any comments or answers is plagiarism by university rules. How can we be sure when we answer questions on this site that we are not fueling cheating or plagiarism? It seemed on these questions, no attempt was made to ask the OP what methods he had tried and no comment was made as to how these seemed awfully homework-like (or in this case, assessed coursework-like). Can procedures can be put in place to ensure that if instances like these are found then the information can be relayed to the university to prevent further cheating/ allow them to take action?


marked as duplicate by Bill Dubuque, Lord_Farin, user98602, Matthew Towers, Ali Caglayan Jan 15 '15 at 17:09

This question has been asked before and already has an answer. If those answers do not fully address your question, please ask a new question.

  • $\begingroup$ Related discussion/answer: meta.math.stackexchange.com/a/9027/23353 $\endgroup$ – apnorton Jan 14 '15 at 20:43
  • $\begingroup$ Suggest you make jpegs of the questions and give to relevant instructor, along with url's I guess. The site is unlikely to help. but the people concerned may still be able to do something. I told a friend that someone was asking questions on material I had published, turned out he was teaching my stuff. He also knew exactly which student it was. However, as is his choice, all he did was make a short announcement that people should not post take-home test questions online. $\endgroup$ – Will Jagy Jan 14 '15 at 20:44
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    $\begingroup$ Totally off-topic remark. I was baffled to find out that in the US homework is used to evaluate students. No such thing is done where I come from. Why should the internet be worried about the US's educational system deficiencies? Why is such a method of evaluation used? It's asking for trouble... $\endgroup$ – Git Gud Jan 14 '15 at 22:43
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    $\begingroup$ @GitGud well, here in the UK I don't think homework is used as assessment often, in this case it is done because the questions take longer than an exam permits. The 5 questions took me a week! With other subjects outside maths though, it is harder to simply cheat on assessed work, given plagiarism detection $\endgroup$ – J_mie6 Jan 14 '15 at 22:49
  • $\begingroup$ Prevent we cannot. We have a reasonable procedure in place for ongoing contests. $\endgroup$ – André Nicolas Jan 15 '15 at 1:23
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    $\begingroup$ For an instructor, "how to assign homework when answers are freely available or attainable online?" could be relevant. $\endgroup$ – jdoicj Jan 15 '15 at 13:00
  • $\begingroup$ IMHO, The best way to stop this is invite the affected instructors to participate in math.SE and let his/her students knows about that! $\endgroup$ – achille hui Jan 16 '15 at 0:41

There are no sure ways to prevent people from using this site as a way to cheat on homework or assignments. You can't look at a mathematical problem and know if the user is asking us to do their homework, or if they are simply stuck while doing some exercises.

The community could decide to simply not answer questions that are simply copy-pasted assignments, and require users to display some effort and context on where exactly they are stuck. But even with those restrictions, it is still pretty easy to post acceptable questions from homework assignments.

Completely preventing users from using the site to cheat is unrealistic, and trying to hard to do this would cause significant harm to honest users using the site. Once you would try to stop anything but the most blatant attempts, there would inevitably be false positives. Agressively shutting down questions that are suspected to be cases of cheating would lead to a lot of conflict, especially when users are falsely accused.

I think requiring users to put some effort into their questions beyond dumping the pure assignment text is a good way to at least deter the laziest of the cheaters.

As for contacting the university, the moderators are not allowed to share any private information about users with third parties. Only SE could release that information, and I strongly doubt that they would do that in these cases, but I can't say this for sure.

  • $\begingroup$ Would it be a good idea for a system to be put in place where universities can submit scripts for assessed-coursework to the SE network, so that any questions asked on those specific questions (perhaps bar one or two isolated incidences from a user, which could be as others have said, innocent self-studiers or other universities) can be torn down and the user perhaps even marked in some way to tell other SEers that they have been known to ask exam questions in the past? $\endgroup$ – J_mie6 Jan 14 '15 at 19:57
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    $\begingroup$ @J_mie6 No. I strongly feel that the effort to pursue this direction well exceeds any profit that it could possibly yield. Also, there's the unavoidable problem of false positives, tipping the balance even further to the conclusion that it is not SE that is to act on this. $\endgroup$ – Lord_Farin Jan 14 '15 at 20:03

Should post something, having been involved a few times. Once I got emailed some questions by an individual, asked for help. I was suspicious and was able to find the longer English phrases from a question on the web. I wrote to the university, eventually the (graduate) student was identified. It was just a slap on the wrist, though, there is enough embarrassment about such a thing that a mathematics department is likely to do little that would allow publicity.

More recently, questions from my publications showed up on MO. I could think of only about three people who would have any interest in teaching my material. I guessed incorrectly, but it was one of them. Alex was teaching a small seminar and knew immediately who had posted the questions. Also, it was a sort of take-home exam, more precisely he told them that the final would be selected from that long list of questions. He told me that the offending student showed up looking green around the gills (after I had made some warnings on MO). All Alex did was make a mild announcement at the end of class that the questions should not be posted online.

More intricate was a girl, maybe three years ago, posting contest questions on MSE under a half dozen usernames. I was only peripherally involved... Eventually it was figured out, and her invitation to the USA summer workshop (for Olympiad hopefuls, I think) was cancelled. Fellow came to tell me about it at the 2013 Joint Mathematics Meetings in San Diego, California.

The worst one for me is still unresolved. Some relatively senior graduate student kept posting disguised versions of a major conjecture in matrix theory, deleting them, changing his username, posting again, both on MO and here. We think he only stopped because he finished his Ph. D.. If he went into industry, or a postdoc with a group that did something specific, he would have no time for that problem.

Oh: in all cases, MSE or MO gave me no information on the miscreants. Took action on my own.


There are a few problems with it

  1. Many universities use the same book, and hence can have similar problem sheets. However, one course may allow for help (for example, many of my university courses don't give compulsory homework, hence they don't account for it in the final grade). Thus, you might be sending completely useless information to university $X$ when it is university $Y$ that has been "dishonored."
  2. The person might be asking the question having nothing to do with a university (consider people that self-study). Contacting a professor and warning him/her about a "mole" or a "cheater" might produce a bad vibe in his/her classroom, which might be totally uncalled for.
  3. Some moderators (and that's to be read "I") might morally oppose a witch hunt -- it would also be too time consuming and tiresome to be worrying about whether this or that question is part of a user's university problem sheet. Personally, I don't think it is my duty to be worrying about another student's dishonesty.
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    $\begingroup$ The OP is asking about a list of question that they know came from an assignment right before it would have been due. It would be very rare for someone not in the class to bombard the site with the exact questions on that assignment. $\endgroup$ – dustin Jan 14 '15 at 19:48
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    $\begingroup$ Whilst I would normally agree with points 1 and 2 there will be cases (such as this one) where you can be very sure where these questions originate, in these cases the university concerned could be contacted. But I can see exactly what you mean in point 3. It would waste quite a lot of time tracking down every possible instance. $\endgroup$ – J_mie6 Jan 14 '15 at 19:49
  • $\begingroup$ However as it is the fellow students degrees that are affected by this, I'm sure there would be students to flag it up for moderator attention as potential plagiarism when they find it, as I have. $\endgroup$ – J_mie6 Jan 14 '15 at 19:52
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    $\begingroup$ @J_mie6 In principle, I agree with you. But what situation are you thinking of where one can be quite sure where the questions originate? A user who posts a question from some course's problem section is not sufficient to conclude they're taking that course - I have used homework sets from other schools as study tools, or maybe their own school is using with permission this other problem set. I guess if the user's profile said "Student at University X currently taking class Y", and posted a homework set from Class Y... $\endgroup$ – user98602 Jan 14 '15 at 19:56
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    $\begingroup$ @MikeMiller but there is also a timing element. The OP is in the class, knows the assignment, and when it is due. What is the likelihood of some other institution using those exact same questions at the same moment in time? $\endgroup$ – dustin Jan 14 '15 at 19:59
  • $\begingroup$ @MikeMiller True, true... $\endgroup$ – J_mie6 Jan 14 '15 at 19:59
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    $\begingroup$ One cannot "morally oppose" something solely because it takes up time, unless that person has a very odd definition of morality. $\endgroup$ – apnorton Jan 14 '15 at 20:44
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    $\begingroup$ @anorton, in this movie en.wikipedia.org/wiki/Now_You_See_Me_%28film%29 Woody Harrelson's character says to Isla Fisher's character " I know you and Danny have unresolved issues. While that is still the case, I'd like you to think of me as your go-to guy for taking care of your carnal needs." Isla says "Thank you, let me ponder your offer of cheap and meaningless sex." Harrelson says "Cheap and meaningless perhaps, but not time consuming." She laughs. $\endgroup$ – Will Jagy Jan 14 '15 at 23:43
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    $\begingroup$ @anorton But wasting time is bad, bad, bad. $\endgroup$ – Pedro Tamaroff Jan 14 '15 at 23:49
  • $\begingroup$ (note however what I am opposing is the witch hunt @anorton) $\endgroup$ – Pedro Tamaroff Jan 15 '15 at 1:07
  • $\begingroup$ @anorton I read point three as two separate clauses. He morally objects to the witch hunt. He also objects to the waste of time. $\endgroup$ – user98602 Jan 15 '15 at 3:23
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    $\begingroup$ Thus, cancel "because"? $\endgroup$ – Did Jan 15 '15 at 6:45

There is no guarantee that any question you answer won't be worth credit for the OP at his or her respected university. If you know the problems come from a graded assignment, you can flag the post for a moderator. In the comment, if you are inclined, you can link to the course or professors website in the flag comment for the mods. This way the mod can close the question and notify the professor if they feel that is the necessary action. If you just want to flag the post and email the professor yourself linking them to the post, that would be your call and nothing would be wrong with it. However, it will difficult for the school to determine the student or students if they are using a random username.

  • $\begingroup$ Is there no way that the university could request the email address behind the account in an attempt to track them down? $\endgroup$ – J_mie6 Jan 14 '15 at 19:30
  • $\begingroup$ @J_mie6 either a mod or a SX employee can answer that since it is due do privacy. $\endgroup$ – dustin Jan 14 '15 at 19:31
  • $\begingroup$ hopefully one pops by :L $\endgroup$ – J_mie6 Jan 14 '15 at 19:33
  • $\begingroup$ @J_mie6 a mod will eventually read this and give you a answer on that or request an official SX response to that if necessary. $\endgroup$ – dustin Jan 14 '15 at 19:34
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    $\begingroup$ @J_mie6 There is nothing stopping universities from requesting email addresses of users, but according to the SE Privacy Policy they won't reveal private information to third-parties, and the moderator agreement makes it an issue for moderators to reveal such information. $\endgroup$ – user642796 Jan 14 '15 at 19:47
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    $\begingroup$ Moderators can get the e-mail address used when creating the account. This is because moderators have a legit need to use it occasionally. However, we are not authorized to disclose that to any outsider. This is written in not so fine print in the moderator agreement. I'm not a lawyer. Try to make sense of SE privacy policy and other legalities here. $\endgroup$ – Jyrki Lahtonen Jan 14 '15 at 19:48
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    $\begingroup$ So my advice to @J_mie6 would be to bring this to the professor's attention, and leave the rest to him. They can look at the answers given to those questions, and possibly use details/style to id a student in violation of the honor code of the university. We don't have the resources to relay these bits to universities. Internet may mean the end of graded homework, take home exams, and such. Sad, but it also brings about many learning opportunities, so IMHO it's the universities that need to adjust. $\endgroup$ – Jyrki Lahtonen Jan 14 '15 at 19:52
  • $\begingroup$ @JyrkiLahtonen That is a very good point, it hadn't occurred to me that they could be tracked down through the style. I will consult them when I get back to uni next week. If people get away with this stuff it just encourages them to carry on, which can potentially ruin their career and affect other students around them. $\endgroup$ – J_mie6 Jan 14 '15 at 19:54
  • $\begingroup$ @JyrkiLahtonen the OP mentions they are in the class. Since IP address have location information, wouldn't it be easy to check to see if both the suspected cheater and OP have IP addresses in the same area? As long as this university isn't on break, they would both be accessing the internet from the same area. $\endgroup$ – dustin Jan 14 '15 at 20:08
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    $\begingroup$ @dustin The moderators aren't allowed to give out the information whether two users use the same or similar IPs. $\endgroup$ – Mad Scientist Jan 14 '15 at 20:09
  • $\begingroup$ @dustin Good idea, but unfortunately the university WAS on break... I doubt he would have done it on the university network, where the university has full power to find him $\endgroup$ – J_mie6 Jan 14 '15 at 20:09
  • $\begingroup$ @MadScientist I am not saying give it out. This would be for the mods to know. $\endgroup$ – dustin Jan 14 '15 at 20:10
  • $\begingroup$ @J_mie6 I don't mean for him doing it on the Uni network. IP address will identify what city you are in. As an example, if you were both using IP address that come back to Hanover, NH, the mods would know you are both probably students at Dartmouth. Then the fact that questions align with a known assignment, at the university in that area, occurring at a set time is extremely coincidental. $\endgroup$ – dustin Jan 14 '15 at 20:14
  • $\begingroup$ @dustin: And if one or both users is using Tor or some sort of proxy, what then? $\endgroup$ – user642796 Jan 14 '15 at 20:15
  • $\begingroup$ @ArthurFischer then the you can't make any hypothesis but most cheaters don't get that elaborate. Having more data to draw a conclusion on isnt a bad thing though. $\endgroup$ – dustin Jan 14 '15 at 20:16

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