What is MO's exact policy on answering or not answering off-topic questions? Assuming there is some well-defined policy. My guess is: you are allowed to answer off-topic questions and if somebody provides a precise, detailed answer to an off-topic question, you should not downvote them. Downvote this post if you disagree.

EDIT: I should have clarified what I mean by off-topic. I mean the following situation: a person gives an answer, after they did this, the question is put on hold as off-topic (e.g. see here). Does their answer also become off-topic, or what?

EDIT: on the main site, YCor says that on this occasion the question was off-topic but the answer was not (since some theorem is not common knowledge). I think this is a non-trivial fact about MO. So answers to questions not of research-level can be research-level?

EDIT: at the the time of the edit, there are 7 downvotes for this question and the score of the linked answer is also 7. I invite the downvoters to downvote the answer so that their actions reflect their views.

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    $\begingroup$ A related older discussion: Answering not research level questions. $\endgroup$ Commented May 20, 2019 at 14:36
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    $\begingroup$ For the specific example behind the link, a better way to handle it would have been to comment why it was off-topic (my reason would be that it contradicts Gelfond-Schneider by work tantamount to an undergraduate exercise) and let others in the community vote to close. I am glad to see the answer anyway. Gerhard "It's Good To Have Reasons" Paseman, 2019.05.20. $\endgroup$ Commented May 20, 2019 at 20:18
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    $\begingroup$ Well, I said that the question was not enough "obviously off-topic" to blame the person who posted an answer. Of course this is a bit subjective, but there's no need to formalize a policy about when it should be blamed and when it shouldn't. Also I wouldn't say it's not "allowed" to answer off-topic questions, it's just not recommended, and this of course depends on one's ability to anticipate that the question will be possibly/certainly closed as off-topic. In this particular case, the question could also have been migrated to MathSE, and the good answer would have been too. $\endgroup$
    – YCor
    Commented May 22, 2019 at 16:43

1 Answer 1


I think previous discussions have covered the ground quite well for this topic, and they should be reviewed. (Hat tip to Martin Sleziak for a link to an excellent starting point.) For ease of reference: there is no exact policy on MathOverflow considering answering off-topic questions. I think a primary reason is that there is some disagreement on what is off-topic.

Even when there is much agreement (e.g. spam, or questions from pre-university math courses), there is disagreement as to how such questions should be treated. In my view, one camp is content with the current level of membership and participation of that membership (level referring both to frequency of posts and degree of technicality/specialization of content), and thus is less inclusive, while other camps are more inclusive, and have a higher level of tolerance for responding to off-topic questions. I belong to this camp because I believe that sustained effort is needed to refresh the population and contribute the material that satisfies me and satisfies the other camp.

My suggestion is to use a comment (in rare cases, an answer, cf 328312 for an example of mine) to indicate that a question is off topic and then (let someone else) vote to close. If you are feeling that a hint is appropriate, include that in your post. As Todd Trimble has quoted, "Be Nice". Down votes can be viewed as not nice. They are also a rough barometer of how well the post fits with the community. Those who downvote with accompanying explanation are helping the community, whether it seems nice or not.

Gerhard "Back To Regularly Scheduled Programming" Paseman, 2019.05.20.

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    $\begingroup$ First this is unclear, saying "this camp" with no clear referent -- perhaps it means the "other camps" as opposed to the "one camp". Then it follows "Be Nice" with an example suggesting not worrying about niceness. Then it violates the policy on signatures and taglines, in this case not even creatively. Gerhard, you can do better than this. $\endgroup$
    – user44143
    Commented May 22, 2019 at 22:03
  • $\begingroup$ @MattF. Then it violates the policy on signatures and taglines Erm... And what is "the policy on signatures and taglines"? I don't think I've ever heard of it before. Perhaps, I'm violating it too and, probably, not creatively as well. That's fine with me but it makes me rather curious :-) $\endgroup$
    – fedja
    Commented May 23, 2019 at 1:25
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    $\begingroup$ @fedja, mathoverflow.net/help/behavior. “Do not use signature, taglines, or greetings” is in bold just after “Be nice”. $\endgroup$
    – user44143
    Commented May 23, 2019 at 6:25

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