Let's say I answer some question, either someone else's or my own (eg this, this or this), on, say, maths se. Then later say I have a class that gives a certain homework and for 1 of the problems in the homework and I decide to use a fact or proof that comes from my answer on the maths se question.

  1. If for some weird reason I cannot find this extremely elementary fact or proof elsewhere on the Internet or in several books I've read, then like what, I have to cite it?

  2. If so and if I use an alias on stackexchange, then do I have to say that it's me? Or can I just pretend it's someone else and cite that anonymous person? (In which case...like...what happens if it's revealed that I am the anonymous person even though I have cited correctly?)

  3. What about research in general, like, say, after you've already gotten a PhD? Eg Does Terry Tao have to cite anything e says on overflow, stackex or wordpress?

These questions might be weird. Actually, I'm not quite sure what's the right question to ask here. Currently, the questions seem to fall under general ideas of self-plagiarism or citing stackexchange. Idk. Personally I prefer to just read other questions already asked about on acad se, even if they're not directly equivalent to the above questions.

  • 3
    What is permissible for class work is up to your professor. You can't get permission here for anything. Ask the instructor.
    – Buffy
    Oct 20, 2021 at 16:24
  • @Buffy hmmm...what about research in general like after you've already gotten a PhD say?
    – BCLC
    Oct 20, 2021 at 16:26
  • Probably not, since anyone can write anything here. Find the original.
    – Buffy
    Oct 20, 2021 at 16:27
  • 1
    @BLCL, you can reasonably include the proof in the new document, and note that it came from the Stackexchange post. If the only source you can find for the fact is your own post, then there's less need to cite it, but you might want to just to cover your bases. When in doubt, talk to a professor or advisor.
    – JoshuaZ
    Oct 20, 2021 at 16:37
  • 3
    Please do not edit meta commentary into your question; the question should just be a question, not a comment on how the question has been received, nor a solicitation for anything besides answers to the question.
    – Bryan Krause
    Oct 20, 2021 at 16:49

1 Answer 1


Let us first check whether not citing the Stackexchange answer could be plagiarism. Since it is your own answer, it cannot. (However, if the question is by someone else it might be best to cite, as the question itself might constitute an intellectual contribution to the answer). If it is not apparent for someone seeing your name and your stackexchange nick that these both refer to the same person, you should cite already to avoid the appearance of plagiarism (and, unless there are strong reasons against it, mention that it's you).

Next on the list, self-plagiarism (badly named, not a case of plagiarism). This concept applies only within formal publications and/or within coursework, so we're clear here.

The final thing to check is whether you need to reference the Stackexchange answer to give proper context of the work to the reader. I'd personally would cite Stackexchange if writing the answer there was an integral part of the development of the paper. If, on the other hand, its just a random accident that some calculation is relevant both in my paper and my answer; if I've already mentioned a proposition from a work in progress on Stackexchange prior to publishing it, I probably wouldn't (unless its about also crediting the asker, see first paragraph).

You must log in to answer this question.

Not the answer you're looking for? Browse other questions tagged .