# What to do about a user repeatedly posting incorrect answers to the same question?

(This question is probably hard to engage with without rep privileges to see deleted answers or mod privileges to see deleted comments - sorry about that!)

A while ago, I posted this question, which got a fair bit of attention. Over the past two years, one user has kept posting answers to this problem, and the following exchange reliably occurs:

• They post an answer that claims to exhibit a counterexample to the OP.

• I, or another user, observe that this doesn't seem quite right, or has misunderstood the question, or suggests false conclusions if its methods were generalizable (e.g. it would suggest unboundedly large solutions, when explicit upper bounds have been proven).

• Some back-and-forth ensues, in which they post dismissive comments suggesting I have misunderstood their answer, and I end up putting some time into carefully explaining exactly where their error lies / which calculations went amiss / where the correctly-evaluated optimum for their family of shapes would be, and why it doesn't improve on the OP.

• They recognize the error, delete all their comments on the answer (and sometimes ask the other users to do the same), and either edit the answer to a slightly modified version or delete it.

This process repeats every few months, with a new answer appearing or an old answer getting a makeover until it presents some completely new approach to the problem. As of this writing, I think it's occurred 5 times.

I have no objections to people making attempts at hard problems and sometimes getting them wrong. But the problem is quite hard (57 upvotes and no solutions after most of 2 years, and a commenter observes that it appears equivalent to a little-known conjecture in the literature), and it seems to me that the user really ought to update about the difficulty of finding a counterexample after considering how many other people have failed to solve the problem, including their past self five times in a row.

At this point I don't really want to keep sinking time into evaluating and responding to their future answers, though I feel a duty as the question-asker to perform this evaluation each time they post a new attempt.

Is there a good approach here? I don't want the user banned or anything, they seem to have a bunch of worthwhile contributions elsewhere on the site and clearly have good intentions. But I've tried gently giving dissuading them already:

As a meta remark, this is now your fourth incorrect answer to this problem. I would suggest updating on the difficulty of this question, and considering this state of affairs as some evidence that the strategy of looking for counterexamples is not likely to be very effective, especially as I would guess that there are no such counterexamples to be found. – RavenclawPrefect Oct 29 at 16:15

and this has not seemed to work. I'd appreciate thoughts on the right course of action here.

• You could just live with it, annoying as that may be. Or, you could flag for moderator attention, since there's really not much anyone but a moderator can do. Nov 16 at 6:11
• Protecting the question can help, if that user has less than 10 reputation. Nov 16 at 7:40
• @TheAmplitwist If only that were the case! The user in question has $\sim 38,000$ reputation. Nov 16 at 9:22
• You could try somewhat less gentle dissuasion. Indicate that while, of course, you appreciate the interest in the question, it is burdensome and unhelpful to debunk these serial pseudo-solutions and request that the user refrain from posting them. My experience in parallel situations is that leaving the door ajar just prolongs the matter.
– lulu
Nov 16 at 11:19
• @TymaGaidash all users with 10k+ reputation can see who posted several (now deleted) answers there. Nov 17 at 2:02
• There are three supposedly wrong answers by this user, and he has 38k reps and 3500 answers on the site. The problem might be too difficult for him, but I don't think there is any reason to complain so far. It looks quite rude to me. Nov 17 at 2:54
• @TymaGaidash Thanks. Bad copy/paste. Nov 17 at 2:54
• (I think you are clear, but ‘update’ feels unusual to me here. Perhaps ‘the user really ought to update their expectations about the difficulty of finding a counterexample’) Nov 17 at 4:18
• @TymaGaidash Yes, I knew about this user, but not that they would behave like here. Nov 17 at 4:39
• The obvious solution is to post, as an answer, that this is an open problem, with an appropriate link, accept your answer, and then ignore it.
– JBL
Nov 21 at 12:48
• @JBL No, that would likely be flagged as "Not an answer", and invite downvotes and delete votes. Nov 21 at 13:56

This is a situation where moderator action is the appropriate way forward.

You have already done everything that you, as a contributor and user without moderator role, can do.

• invisible answers are irrelevant to anybody who can't see them, so there is no reason to point them out

• non-deleted answers are visible along with comments pointing out their defects; putting those comments elsewhere is making them less helpful to everybody else, making them general instead of particular to the answer is not constructive and therefore inappropriate

• making declarations about your refusal to interact with someone are unwelcoming at best and potentially conflict-creating, and also totally unnecessary; you don't have to tell us that you're not saying more, you just don't say more

This situation is an exception to the normal. Moderators are the exception handlers. Helping with this kind of case is literally their elected role.

A moderator can determine whether they need post deletion, private discussion, formal warning, suspension, escalation to higher levels, something else, some combination of these, or nothing further at all.

So, flag for a moderator, downvote the answers if you think it is right to do so, and ignore them from there on.

• I believe we all agree that flagging a wrong answer for moderation is not appropriate. Downvote, explain in a comment why it's wrong, ok. So the point is, is there clearly an abusive behavior - then it's ok to flag. But really, three attempts, that looks like a minor misdemeanor. And it's not even from the usual soon-to-be-blocked troll. I'd ponder (and I expect a moderator would too) what's best for the site: risk loosing a good contributor who let his passion take him a bit off rails, or kindly explain. Nov 18 at 21:30
• You say that like they're two distinct options, and also the only options available. Some people get upset when they're politely told the expectations and how they're not being met; good contributors include those who ask great questions and they are at risk of leaving when someone keeps adding foolishness without consideration for the effect.
– Nij
Nov 18 at 21:39
• I have too been on occasion so convinced a proposition has to be true that I made several wrong attempts before pausing to think (not on this site, but it does not change the feeling). Foolishness? Maybe. Let any one of you who is without sin be the first to throw a stone at him. Nov 18 at 21:45
• The offending user has to be made aware of the problems he is causing. Ordinary users don't know who he is, but hopefully a moderator (or someone else) can direct him to this post so he can reflect. Nov 19 at 0:13
• @Jean That applies to you, as well. It's not a question about flagging a wrong answer; it's a suggestion when one user repeatedly posts wrong answers, and does not recognize that they are repeatedly trying and posting attempts that have been "done that, been there." And that scenario does lead me to think that flagging for mod attention has become necessary. I'm with Nij on this, "Flag for moderators' attention," so please don't throw stones in Nij's direction. Nov 19 at 22:12
• @amWhy I'm not the one throwing stones. Anyone is entitled to flag for moderator attention, and it's only my humble opinion that it's undeserved here. Well, let moderators decide what to do. Nov 19 at 23:54
• Exactly. Flag for moderator attention and let them decide what to do. You are arguing against doing the only thing that can assure the desired result...
– Nij
Nov 20 at 0:40