A user X answered my (some one else's) question in a compact way (less than $$10$$ lines).

Upon discussion, user X has explained somethings in comment which made answer clearer.

Is it considered to be a bad practise to add details (limited, say 5 lines) to some one else's answer to make it clearer for others?

• One option is to post an additional answer, maybe cw (notably if it just repeats or slightly expands comments), saying that this is a detailed version of X's answer.
– YCor
Feb 21, 2019 at 22:12
• @YCor I did that in some of my questions.. there was no positive feedback in that case.. Feb 21, 2019 at 22:19
• What kind of positive feedback would you expect? upvotes? Possibly if there was no upvote means that the additional answer was not considered useful, or that people were not interested in the question (for this, compare to the number of upvotes to the question). It's not a judgement (I'm not close enough to your subject, just a general assumption). But certainly if it's not upvoted, it would not be more appreciated as a modification of an answer. Indeed conciseness might be a choice from the answerer and can be appreciated if it's well-balanced.
– YCor
Feb 21, 2019 at 23:25
• @YCor by positive feedback I mean a comment saying “this looks ok” or something like that... I am not after upvotes :) :) I completely agree with “if it's not upvoted, it would not be more appreciated as a modification of an answer”... thanks for the feedback... :) Feb 21, 2019 at 23:30
• Comments are not meant for this kind of "positive feedback". A comment that says only "this looks OK" should have been an upvote. Feb 23, 2019 at 8:53
• @FedericoPoloni ok Feb 23, 2019 at 9:12
• @PraphullaKoushik when something like this happens, I would definitively put your answer as "community wiki" (and say so in the first line of your answer). I'm not sure if this is the case, but some people might think you are fishing for upvotes (even if you don't care). Also they would not comment like "looks good" because this is not what comments are for.
– ARG
Mar 5, 2019 at 13:08

I think so. The detail is all there, even if spread into the comments; it's what they are for. If further expansion is needed, why not just ask the person who wrote the answer to expand it? But, as you say, if this is only for the sake of third parties, can they also just read the comments? Or, ask in the comments for clarification themselves?

[Added, as requested] If others are satisfied with the answer and worth upvoting, or even giving the little tick, then this should indicate something about the quality of the answer in they eyes of other users. One should perhaps pause before writing what amounts to a page or more of detail. Sometimes these things seem important at the time, and sometimes after a little reflection it becomes clear why a short answer was completely sufficient. Or, it really wasn't obvious, and there was a trick that, once understood, made things a lot more clear. Then it might be that the trick is what is missing, not routine detail.

• meta.mathoverflow.net/questions/2528/… user 7092 says there “For example, comments are not (at least not easily) searchable and are generally deemphasized (this is even more the case on some mobile versions than on full site).” Feb 21, 2019 at 7:39
• I understand there is no one rule which works for all kinds of questions... :) :) If I really want to edit, I will simply ask permission from the user who answered... That is the best I can do... Feb 21, 2019 at 7:46
• BTW in the linked question it is user9072 (no 7092) - which to all old timers is familiar as quid. (The username before they decided to delete their account.) Feb 21, 2019 at 7:59
• @MartinSleziak yes, I heard about quid Feb 21, 2019 at 8:41
• In addition to the non-searchability of comments: They are impermanent and can be deleted at any time under far less demanding conditions than questions and answers can be. MO very rarely does this, as most of the comments here are on-topic discussions about the mathematics/question at hand, but it remains possible that a "clean up" will be initiated and a lot of these comments lost. They also cannot be down-voted, meaning you cannot trust the assessment of their worth as well as you can an answer. MO rarely has problems with this, too, but it remains an unadvised dependency on site culture. Mar 5, 2019 at 7:41

My personal opinion is that there are two options, depending on the situation:

• You could post a separate answer, clearly explaining that this is a more detailed elaboration of the other answer - both to get some feedback to your approach (which helps you to see whether you understood it correctly) and for the benefit of others reading the same answer.
• Adding this to the answer, but mentioning explicitly in comments why you have added this and making clear that you consider this useful, but the OP should simply rollback the edit if they prefer the version without your addition. (Theoretically you could ask first, then edit, then ask again whether the new version looks ok - but by editing right away you save one round of this exchange.) Apart from the comments, make it clear also in the edit summary why you are making the edit.

The first option is suitable only if your post will be long enough to varant a separate answer. (From the description in your question it seems that this is probably not the case here. Still, if this is at least a bit feasible, to me this seems as better option than a larger edit to somebody else's post. So it is a judgement call: How big change does your edit actually make? Could this post be better as a separate answer?) One more benefit of posting is separate answer is that you are the owner of the post - so you have more control over the content of the post.

Let me still stress one thing - the final look of the answer should be the decision of the answerer.1 It is natural to assume that editor acts in good faith and tries to make some improvements. Minor edits (typos, forgotten dollar, some MathJax mistake, updating dead link) should be fairly uncontroversial. But if you want to make a larger edit, it is important to ask whether the answerer agrees with it. In particular, don't to this if the answerer wasn't online for a long time2 and it is unlikely that they will be able to respond to your edit.

From this viewpoint it is a minor advantage to you that all your edits have to be suggested edits (until you gain 2k reputation points) - which means that the answerer can reject the edit by one click in the suggested edit review.3 (For suggested edits, the edit summary is even more important, since you want the reviewers to see why you want to edit the post.)

TL;DR: Yes, this can be done - but only in some cases, so don't overuse it. Always ask whether the OP agrees with the edit. If the edit is long enough to make a separate answer, that might be a better option. In such case, make it clear in your answer that it is your elaboration of the details of another answer.

1A possible exception are community wiki posts, which are intended for collaborative editing by the community. (Although on this site it is sometimes used to avoid getting reputation for the post - contrary to network-wide guidelines.)

2You can check the OPs profile to see when they were last seen on the site.

3The OP has always final word on the suggested edit, even if it has already been approved by other users. See: Could authors overturn recent community review decisions? and the relevant section of How do suggested edits work?

• Can you please tell what you mean by “then one should reflect on how others see that answer to so react”?? @DavidRoberts I understand other lines only this I don’t understand... Feb 21, 2019 at 11:22
• If others are satisfied with the answer and worth upvoting, or even giving the little tick, then this should indicate something about the quality of the answer in they eyes of other users. One should perhaps pause before writing what amounts to a page or more of detail. Sometimes these things seem important at the time, and sometimes after a little reflection it becomes clear why a short answer was completely sufficient. Or, it really wasn't obvious, and there was a trick that, once understood, made things a lot more clear. Then it might be that the trick is what is missing, not routine detail Feb 21, 2019 at 11:31
• @DavidRoberts Please add your last comment in your answer here.... It makes so much sense... "Sometimes these things seem important at the time" This is precisely the reason why I write 1 page detail :) :) "One should perhaps pause before writing [---]" I will, from next time... :) Feb 22, 2019 at 15:01
• @PraphullaKoushik done. And I am fully aware of the irony of the situation :-) Feb 22, 2019 at 23:50

I did this once, here. I was going to answer the question, but Andy did it first. I still felt there was some value in the remarks I was going to add, but it felt strange to do it in a new answer, and it would not have the same reach if I just added the remarks as comments. So I edited Andy's answer to include the information, while attempting to make it clear that of course it could all be removed if it was deemed preferable.

I think, however, that situations such as this one are rare and advice much caution before acting similarly.

• This was also 6 years ago, and community norms may not be the same now as then; there was a much tighter-knit group of core users regularly interacting with each other, I feel. Feb 23, 2019 at 12:03
• @David Re "advice", it probably depends on where in the world you live. I agree with the second comment. Feb 23, 2019 at 13:40
• ah, I see. That's a new cross-Atlantic (Pacific?) difference for me :-) Feb 23, 2019 at 16:18

It is ok but the extra material should be separated from the original material and clearly labelled as written by someone else.