I have a request. It would be nice if the moderators here would avoid migrating low-quality questions to CS.SE.

I noticed recently a few low-quality questions that were migrated to the Computer Science Stack Exchange (CS.SE) site. I would suggest that we avoid doing that.

  • If it's a good question, and on-topic for CS.SE, I definitely encourage you to migrate to CS.SE. For instance, if it is not research-level but would be a reasonable question, migrating to CS.SE is a great idea. Go for it!

  • But if it's a bad question -- one that would be a bad question for CS.SE -- please don't migrate it to CS.SE. If it's a bad question, just close it, don't migrate it. Please don't make CS.SE a dumping ground for bad questions.

  • If it's a good question -- well-researched, on-topic, focused, narrow -- but has some English/grammar problems, don't let that stop you from migrating. If it's just the English, we can edit it over at CS.SE. But if it is a fundamentally bad question -- e.g., not well-researched, or a duplicate, or unclear -- I personally don't think it should be migrated over to CS.SE

One recent example: https://cstheory.stackexchange.com/q/18536/5038. In my opinion, that question shouldn't have been migrated to CS.SE. It is not a good fit for the Computer Science Stack Exchange. The question does not show evidence of effort. It asks a question about a topic that is already covered by reference questions at CS.SE, with no evidence that the question-asker was aware of that. These issues are not something that those of us at CS.SE can fix through simple edits to the question. Of course, that's just one example. I don't mean to pick on that one or focus on that one too much.

Kaveh explains that the CS.SE admins specifically requested that "badly written" questions are still OK to migrate to CS.SE. I didn't realize that! That explains a lot. Perhaps that's something we should discuss. I'm not sure whether "badly written" refers to the English/grammar, or to more fundamental issues (like whether it's a good question, whether it is well-researched, whether it is on-topic and focused and detailed and not a duplicate). If the former, I agree, English/grammar problems should not be a barrier to migration. If the latter, well, I guess I might have a slight difference of opinion with the CS.SE admins -- maybe that's something we need to discuss on CS.meta, instead of here.

I certainly don't mean to imply that this is a huge, systemic problem that requires major changes to migration, and I don't mean to imply the moderators here are doing anything wrong (I think the moderators are doing a great job!). Overall I think the process is generally working well. I just wanted to suggest a minor refinement that I think might make things work better on CS.SE.


  • $\begingroup$ the question uses the "bad" adjective as if it is an objective, not a subjective criteria. the use of the term "badly written" by K was probably not exactly accurate & merely a hastily chosen/poor choice of words at the time. obviously no stackexchange anywhere is volunteering for "badly written questions". moreover note that there is only a small trickle overall of questions from tcs.se → cs.se. but yeah, the exact criteria for migration in both directions [currently sketchy as you point out, also adhoc, case-by-case] deserves attn/clarification. $\endgroup$
    – vzn
    Aug 5, 2013 at 17:59
  • $\begingroup$ Thanks, @vzn -- I completely agree! Clarifying the guidelines for migration seems like the right goal to me too -- and it sounds like the discussion resulted in a great set of guidelines. $\endgroup$
    – D.W.
    Aug 5, 2013 at 23:35
  • $\begingroup$ I think it's a bit strange that your example of a bad question for CS.SE currently has 37 upvotes. $\endgroup$
    – Lev Reyzin Mod
    Aug 8, 2013 at 15:14
  • $\begingroup$ @LevReyzin, If you're referring to me: the question I linked to, which was migrated from CSTheory.SE to CS.SE, currently has its vote total at -2, not 37. Perhaps even more relevant, once it arrived on CS.SE it was almost immediately closed (because we have a reference question that already describes how to answer it). The reference question currently has a +37 vote total, but I'm obviously not suggesting the reference question is a bad question; I didn't link to the reference question, I linked to the bad question that was migrated. Perhaps you mixed the two up? $\endgroup$
    – D.W.
    Aug 8, 2013 at 18:02
  • $\begingroup$ I guess I am confused. I am talking about the question "Omega of a polynomial function" which is the only one linked-to. I see it as +37. $\endgroup$
    – Lev Reyzin Mod
    Aug 8, 2013 at 18:11
  • $\begingroup$ @LevReyzin, I don't know why you see it that way, but when I click on that link, it takes me to "Omega of a..." which definitely shows up as -2 and is closed (it is marked as a duplicate of "How does one know...", which is +37). Here's the link again, for your reference: cs.stackexchange.com/q/13578/755 $\endgroup$
    – D.W.
    Aug 8, 2013 at 21:14
  • $\begingroup$ This explains the confusion -- how bizarre! The link you just posted takes me directly to the question "How does one know...", which is +37. $\endgroup$
    – Lev Reyzin Mod
    Aug 8, 2013 at 21:30

3 Answers 3


I propose the following guideline: suppose you're teaching a computer science class and a student comes to you with that question. How do you respond?

In a nutshell, if you just wish the guy would go away, close in situ. If you'd like to help the guy (and the question is about computer science), migrate. In more detail:

  • “What? Is that even English?” → Close (“unclear”).
  • “Go read this book.” → Comment, close (too broad).
  • “A chimpanzee who'd attended the class would know the answer!” → Close (“unclear”), pray to that the user doesn't come back.
  • “What does this have to do with me?” → Close (off-topic).
  • “It's a matter of taste.” → Close (opinion-based).
  • “That's a direct application of something we covered in class.” → Close (“off-topic, not research-level”), point to a Wikipedia page or to a CS.SE reference thread on the topic (e.g. How to prove that a language is not regular?).
  • “That's a good question about computer science! You see…” → migrate to CS.SE.
  • “Ok, here's a hint to solve this exercise, try it and come back.” → migrate to CS.SE.
  • “Gee, a programming question.” → migrate to SO if you think it's a really good question, otherwise close as off-topic.

If none of the categories applies, use your judgement. There is obviously room for subjectivity. Where does Omega of a polynomial function fit? I would close and answer with a comment linking to Wikipedia, because it's a really elementary question. Also, technically, it isn't a computer science question, it's a math question that falls short of reaching a CS application. I wouldn't say that migrating it is fundamentally wrong, but it is a bit of a waste of effort.

If in doubt — if the question is not great but not crap either — you might as well migrate. If the target site doesn't like the question, it can close it.

  • $\begingroup$ Those sound like reasonable guidelines to me! $\endgroup$
    – D.W.
    Aug 5, 2013 at 1:55
  • $\begingroup$ This is an excellent set of guidelines. $\endgroup$ Aug 5, 2013 at 6:04
  • $\begingroup$ I also agree with this except with “A chimpanzee who'd attended the class would know the answer!” and the case where the question would be closed a duplicate on Computer Science. I think this is more about the scope of Computer Science so I will discuss it on Computer Science Meta. $\endgroup$
    – Kaveh
    Aug 5, 2013 at 8:01
  • 1
    $\begingroup$ If in doubt, you can always ping us in chat (via bot/script in the mod loungs). $\endgroup$
    – Raphael
    Aug 5, 2013 at 20:35
  • 1
    $\begingroup$ @Raphael, we do as you know but I will do that more. :) $\endgroup$
    – Kaveh
    Aug 6, 2013 at 5:24

A small note and update about migration

As you know only moderators can migrate questions to CS.SE right now and this is unlikely to change until CS.SE graduates. I think Suresh generally does not migrate questions, Dave does sometimes, but most of the migrations to CS.SE was performed by me.

Since the discussions here and on meta.CS.SE I have stopped migrating questions except in very special cases because people do not seem to be happy with them and migration has become too complicated (check if there is a duplicate or reference questions, etc.). In practice questions are either OK here or not OK there.

So in practice we don't migrate questions to CS.SE anymore. Please keep this in mind when commenting or flagging for migration.

  • $\begingroup$ Please also edit close or flagging reasons, because right now, a question which is not research level is off topic, and in the off topic lists migration to cs.se and to other sites or correctness of unpublished paper are listed, and the only category fits with this is first one (migration to cs.se). $\endgroup$
    – Saeed
    Sep 24, 2013 at 8:53
  • $\begingroup$ So if a question is a bad fit for cstheory but a good fit for cs.se, is the correct response to comment on the post suggesting that they repost at cs.se? $\endgroup$
    – usul
    Sep 24, 2013 at 14:49
  • $\begingroup$ @usual, you can do what we were doing before migration: close the question, comment and suggest OP repost it there. $\endgroup$
    – Kaveh
    Sep 24, 2013 at 15:20
  • $\begingroup$ @Saeed, close reasons do not mention migration. In any case, if you want to suggest a new close reason please post it as an answer in the question for custom close reasons. $\endgroup$
    – Kaveh
    Sep 24, 2013 at 15:22
  • $\begingroup$ Ok I see you just updated that question, actually I cannot close question right now, I mean this branch of flagging: Flagging>Closing>Off-Topic. But is better to also mention it here (e.g linking). $\endgroup$
    – Saeed
    Sep 24, 2013 at 15:38
  • $\begingroup$ Is this still the current stance, given that CS.SE has graduated (is no longer in beta)? $\endgroup$ Oct 30, 2015 at 22:27

Right now only moderators can migrate to [cs.se] and all of them more or less participate on [cs.se] and know its scope. So I don't see the relevance of the parts of your post about not being familiar with the scope of [cs.se].

AFAIR, the last thing I heard from [CS.SE] admins was that it is fine to migrate questions that are in the scope of [cs.se] even when they are badly written, they can be dealt with them over [cs.se].

I know the reference question. I migrated the question so it can be closed as duplicate on [cs.se] since we cannot close them as duplicates on cstheory.

  • 1
    $\begingroup$ OK, then I will edit my request to remove the comments about familiarity with CS.SE and re-focus on not migrating questions that are bad. Thanks for the information about what you've heard from CS.SE admins -- I wasn't aware they were taking that position. Personally, my request is: if it would not be considered a good question at CS.SE, please don't migrate it. If the problem is just poor grammar or poor English, no problem. But if the problem is more fundamental -- e.g., lack of prior research, etc. -- I would personally prefer that those questions not be migrated. $\endgroup$
    – D.W.
    Aug 2, 2013 at 21:59
  • $\begingroup$ @D.W., I personally think migrating these questions works better for cs.se. I think users take it more positively when their question is migrated to Computer Science and answered or closed as duplicate than just closing as off-topic on cstheory with a comment pointing to Computer Science, and more likely to result in their participation. If this creates too much work on Computer Science then we can stop this but right now I think there are not that many. $\endgroup$
    – Kaveh
    Aug 2, 2013 at 22:07
  • 1
    $\begingroup$ Kaveh, when the question is a good one, I certainly agree with you that migration helps the poster a lot more. But if it's a bad question? If we look at that particular question, I don't see what good can come of migrating it. The problems with that question are fundamental, and cannot be fixed through simple edits. That's a low-quality question where the only thing we on CS.SE can realistically do with it is close it. That's just creating extra work and broken windows for folks at CS.SE. And are users going to take it positively to have their question downvoted and closed anyway? $\endgroup$
    – D.W.
    Aug 2, 2013 at 22:11
  • $\begingroup$ To elaborate: If we're migrating a question over to CS.SE just so it can be closed as a duplicate, then I'd question whether that's really more friendly to the poster. (Also, in this case, someone on CSTheory already mentioned that the poster should read the reference questions on CS.SE, so in this particular case, I don't see much point in migrating it to CS.SE just so it can be closed as a dup of a reference question.) More broadly, it's not just the extra work on CS.SE; there's also the "broken-window" effect of having more bad questions on CS.SE, which has broad but unmeasurable effects. $\endgroup$
    – D.W.
    Aug 2, 2013 at 22:14
  • $\begingroup$ @D.w., I don't think it creates a broken window effect if an unsalvageable question is closed. CS.SE is in beta and in my experience many users don't even know it exists or what is the difference between the scope of cstheory and cs.se and if they did they would ask the question on Computer Science. In these cases I lean towards migrating the question if I feel the question can be salvaged or if it can be closed as duplicate. I think any reasonable user asking almost any of the migrated questions wouldn't have asked it on cstheory if they showed effort and read help center so I don't think effort $\endgroup$
    – Kaveh
    Aug 2, 2013 at 22:22
  • $\begingroup$ should play a big role in deciding what to migrate or what not to migrate to Computer Science. I would love if new users read comments after their question is closed but it looks that they often don't. If I could close as a duplicate of a question on Computer Science I wouldn't need to migrate, but right now we cannot. $\endgroup$
    – Kaveh
    Aug 2, 2013 at 22:24
  • 2
    $\begingroup$ “The last thing I heard from Computer Science admins was that it is fine to migrate questions that are in the scope of Computer Science even when they are badly written” Er, what do you mean? If you mean questions in need of editing for grammar and formatting, sure (though editing first is always appreciated). Or questions from a confused student that are nonetheless answerable. But not questions that are nonsense, or not about CS. $\endgroup$ Aug 4, 2013 at 23:34
  • $\begingroup$ @Gilles, sure, I didn't mean questions which are nonsense or not about CS. I think the main category that D.W. is objecting to its migration is those questions which are not nonsense and are on topic on CS but the OP has not shown enough effort to find an answer. Should I refrain from migrating these to Computer Science? E.g. if we get an undergraduate question about algorithms or formal languages (e.g. what is the DFA for the following regex, etc.) should I refrain from migrating them to Computer Science? $\endgroup$
    – Kaveh
    Aug 4, 2013 at 23:43

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