According to the help center, comments should NOT be used to answer questions. However I see many answers in comments. Other stackexchanges have a policy of deleting answers written in comments. We should have the same policy.

The logic is that there is no quality control. There are no downvotes to ensure that the answer is actually helpful.

• It would be unfortunate to delete such comments, since if they really do answer the question and help the OP then those comments are useful and add value to the site. Would it be a bad idea to instead allow users to flag a comment as "should be posted as an answer," and allow a moderator to move the content of that comment to an answer? – Mike Pierce Jul 5 '18 at 14:19
• @MikePierce other SEs delete such comments and seem to be doing fine. Although being converted to answer would at least be something – user223391 Jul 5 '18 at 14:22
• There is more logic; comments are not presented to the reader in a manner suitable for displaying answers. – user14972 Jul 5 '18 at 14:38
• I'm concerned that this would sacrifice some of the helpfulness of this site to students just for the sake of "playing by the rules." I've gotten help countless times by reading the comments on unanswered questions, since those comments basically flush out the answer anyways. – Mike Pierce Jul 5 '18 at 14:39
• (Not to point fingers, but) I've seen this a lot on algebraic-geometry and algebraic-topology tagged questions, I suppose just because full answers to those questions can be really long, and the answer-er would prefer to give a sketch of answer that they feel is only appropriate as a comment. – Mike Pierce Jul 5 '18 at 14:40
• I don't see the point of deleting potentially useful content simply because (in the opinion of the commenter) it didn't merit a full answer. For that matter, there's not even a built in mechanism for high rep users to do so. Of course, anyone can flag a comment but putting this on the moderators seems an undue burden. – Mark McClure Jul 5 '18 at 15:13
• One thing I'll note: I have not been terribly troubled by legit hints (not answers cloaked as hints) posted in comments occasionally; if the asker (willing) can use a hint to break a block in their understanding, and put two and two together to realize the answer, I think learning has occurred. But if a hint is offered in the comments, and the user's only response is and immediate "Please answer me with full, step-by-step solution. To get credit on my homework (or test), I need to have step-by-step-justifications", ... – amWhy Jul 5 '18 at 20:17
• ... that's a clear signal to any sane human being that any further hints, answers, solutions, is just giving what the asker wants, in exchange for comment upvotes, or answer upvotes? – amWhy Jul 5 '18 at 20:18
• Jeez. If a comment is abusive, by all means submit a flag. But a comment that happens to answer the question is anything but. What harm is it doing? If you feel it should be an answer, then make it your answer! – Ron Gordon Jul 5 '18 at 20:34
• Much of the help center is just wrong - it was written by people who had no real experience with this site, without asking for our input, and we often have no way to edit it. – Carl Mummert Jul 6 '18 at 19:03
• @RonGordon: The problem isn't that one person did it once. The problem is that a lot of people do it often. – user14972 Jul 6 '18 at 22:33

While Comments are properly used to make clarification requests and tangential observations, not answers, and Answers should provide solutions justified by mathematical reasoning, I fear the proposed deletions of Comments are an invitation to "throw out the baby with the bathwater."

As I've previously stated, if someone feels I've given an answer in a Comment, the OP or another community member should feel authorized to post an Answer based on my Comment. This often happens when I've suggested an interpretation in a Comment that leads to a quick solution, based on the uncertainty that such a short treatment would really address the OP's problem. I justify such an exchange as a request for clarification, and I'm willing to "risk" that others will capitalize on such a request to provide a good Answer.

More crucially how would the proposed deletion of Comments be moderated? We cannot individually delete Comments, but must rely on flagging for Moderator attention. There would be no queue to review such flags, and thus it will ultimately require the Moderator to judge. Of course once an Answer is posted incorporating the information in the Comment, then a good argument can be made that the original Comment is obsolete/no longer relevant.

In general my feeling is that many Questions are in need of improvement before being suitable for retention on the site, and a certain amount of discussion in Comments has to be tolerated to bring them "up to snuff", e.g. adding suitable context.

I'm also sympathetic with Questions that provide context that comes agonizingly close to a solution. It seems to me that "hints" to close the gap in Comments are preferable to "hint" style Answers. Nevertheless the Community winds up tolerating many such Answers, and it should not (in my opinion) be a rationale for deleting (or forbidding) equivalent Comments.

Ultimately I prefer detailed Answers for all valid Questions because of the benefit to future Readers.

• "More crucially how would the proposed deletion of Comments be moderated?" How it is successfully moderated by other sites – user223391 Jul 5 '18 at 15:17
• I'm not aware of what success you claim for other sites, although I'm somewhat involved with a variety of StackExchange communities, esp. StackOverflow as an example of what you might be thinking of. I think you are in a better position than I am to explain which sites make use of such a policy. As I tried to say, the ephemeral nature of Comments does allow eventual deletions once a valid Answer is given. I'm opposed to a priori "censorship" not to a posteriori removal. – hardmath Jul 5 '18 at 15:23
• This happens, that some users deliberately upvote very poor posts that won't stand a chance, one revolving-door user even creates multiple accounts, and replaces each after every deletion of one of their accounts by moderators, due to their chronic abuse of upvoting questions through the use of multiple accounts, and answering questions almost, or already closed. Your examples or cases do not cover this deliberate abuse. (BTW - See "elbow: LB_O in the comments below the question. They appear, as a braggart, and entirely disrespectful to Zachary, in comments below Zachary's question. – amWhy Jul 5 '18 at 19:53
• The mods have acted wrt LB_O, whose account has since been deleted. Again. And again. – amWhy Jul 5 '18 at 19:56
• hardmath See also my comments below this meta question addressing the existence of that repeat offender. There is and has been a problem with this individual, and certain users that upvote anything they answer, who answer anything whatsoever (i.e. a handful of rep-farmers on MSE do this, thinking they'll get more credit (i.e., rep) if the questions they answer have a higher vote count than they would have otherwise. – amWhy Jul 5 '18 at 20:04
• @amWhy: I credit your concerns, and would be happy to discuss with you (my email isn't hard to make out), but I'm not sure how sock puppets, rep-farmers, and gratuitous up-voting of poor Answers relate to the main issue here, answering Questions in the comments. – hardmath Jul 5 '18 at 20:12
• The user to whom I refer intentionally creates multiple accounts at any given time, one of which was the now deleted LB_O account, to spend all up/down-votes by upvoting very poor questions, often already closed. The other activity they engage in, is answering questions which have been closed, through the use of comments. As we all know, one of the reasons users who vote to close a question is for it to be improved, and no more answers be allowed unless and until the question is reopened. The user I speak of, through multiple accounts, snubs their nose at that, ... – amWhy Jul 5 '18 at 20:23
• ... says, essentially, "screw you all", and proceeds to answer closed questions in comments. I agree that some users use comments well, in a helpful manner, to offer a hint, to help the asker and other users to clarify what the question is, to suggest improvements to the question, etc. But there are also users who misuse comments, as I describe above. I'll give you that the majority of users use comments with the best of intentions. But other, not so much. – amWhy Jul 5 '18 at 20:27

I think it's helpful to separate occurrences of this happening into two categories:

• Sometimes the question being asked is based on a slight error or misunderstanding on the part of the OP, and all their problems can be solved with a quick comment like, "you dropped a negative there," or "you're close, but just change this to that." These comments don't seem appropriate as answers. Posts like this, after the OP gets help, don't really add quality to the site, so I would vote to close these as Off-Topic > Other > "It was a poor questing stemming from a simple error that was resolved in the comments.".

Note that userXXX has answered this question in the comments. I've posted (and possibly expanded on) their answer here, so that users of the site who confidently concur that this answers the question may upvote it.

• I would go even further and say that new users to the site should be actively encouraged to take the second of these actions (minus the CW part) whenever they see such a post. It's an accessible way to clean up and add value to the site, to earn some initial reputation, and to get introduced to the community. Unfortunately I don't see such answers getting many upvotes (everyone needs to upvote more!!!) so new users won't see this as being worth their time. :c – Mike Pierce Jul 5 '18 at 15:11
• I have definitely answered questions with comments in the first case. I agree that the correct approach in those cases is (1) vote to close the question as off-topic, (2) leave a comment explaining the issue, and (3) perhaps downvote the question so that it can get Roomba'd up later. I think that your analysis of the second case is also quite reasonable. – Xander Henderson Jul 5 '18 at 15:49
• This happens, that users deliberately upvote very poor posts that won't stand a chance, one even creates multiple accounts, and replaces it after every deletion of accounts by moderators, due to their chronic abuse of upvoting questions through the use of multiple accounts, and answering questions almost, or already closed. Your examples or cases do not cover this deliberate abuse. (BTW - See "elbow: LB_O in the comments below the question. – amWhy Jul 5 '18 at 19:50
• Mike: That account (LB_O) has been deleted by the mods, after their being made alert that this person was back with yet another account. They are known to the mods, and I'm surprised they are not better known by more users who've been around awhile. – amWhy Jul 5 '18 at 20:05
• One possible reason to answer in comments is to discourage others from posting more complete answers, while a question is waiting to be put on hold. Of course, as amWhy writes, others answer in comments after a question is put on hold. – Carl Mummert Jul 6 '18 at 19:04

Disclaimer:  I am among those with a fair share of what borders answers in comments, sometimes strong hints, though never a complete answer.

I believe that the asker of a question is often better served by pointing them in the right direction, rather than providing a full answer upfront. Down the road for them, that's the difference between remembering it as "I figured that out once, so I can do it again on my own now" vs. "I got the answer on MSE last time, let me take that shortcut again".

How MSE views/taxes such comments is, in the end, an inherently conflicting matter. On one hand, the site manifest says "MSE is a question and answer site for people studying math at any level and professionals in related fields", which would seem to imply that it's meant to help those very people who are asking the questions. On the other hand, it also says that "we're working together to build a library of detailed answers to every question about math" which moves the target away from the askers onto the future readers/google'rs. The two goals are not necessarily always aligned.

(For a crude example thereof, marking a PSQ as a duplicate is AFAICT welcome, even though that provides the most instant gratification to the asker. In contrast, answering a PSQ is a no-no.)