Why do people answer in comments?

Question

Browsing TeX.SE, I have noticed that very frequently people provide answers to a question in the question's comments.

See for example

BibTeX error "inputenc Error: Unicode char \u8: not set up for use with LaTeX"

Is there any package for LaTeX dealing with a database?

How to correctly set up Palatino font with math (related to pxfonts)

This is very different from other SE sites where people tend to provide a lot of answers, and the best one(s) appear at the top by voting.

I am asking because for several unanswered questions I would like to provide an answer, but then I see the very same answer has been submitted as a comment, so I think "ah well, this would look like cheap copying, I rather leave it".

Effectively this seems to leave questions technically unanswered where in reality a pretty satisfying answer exists. To me, this habit seems contradictory to a Q&A site.

Answer 1

There are two ways in which you can view a Question/Answer site. One is as a real-time "I've asked this question and I want a quick answer now" type of site, and the other is as a longer term repository of questions and definitive answers. I think that many of us here take this latter view of the site. As a result, we have lots of very high quality answers, and a relatively low number of competing answers for many questions. We also tend to comment on answers to improve them rather than posting competing answers. This is a very good thing, IMO and not only makes the site a useful long term resource, but also fosters a real sense of community where people are willing to help each other rather than fighting over reputation.

I think that having lots of competing answers to any particular question just generates noise and makes the site less useful. Also, as you can see from other sites where this practice is more common, when there are lots of answers, early answers tend to get upvotes and very good but later answers sometimes don't.

The commenting facility however, provides a real time remedy to this situation: a comment that also provides an answer may solve the original questioner's problem, and (as others have noted) at the same time provide time for us to find and link to other related or duplicate questions. This again adds to the value of the site.

Answer 2

In general, you are correct that something which answers the question should be given as an answer. However, there are some subtleties to this. The first is as marczellm says that a one-liner may not really 'feel' like an answer: it may be the core of an answer but need expansion, for example. There is then the question of whether the comment really answers the question, which you might want to check out. Not all questions are great, and some of them you may want to comment on with the expectation that they'll be closed. That's particularly the case when you're posting something that can be found in a simple guide or with a web search.

During our 'Answer the Unanswered' sessions, one of the things that happens is that people are encouraged to convert comments to answers where this seems the best approach. (That's done by leaving a comment asking the earlier commenter to take action: I use @<person> Looks like an answer to me.) If the original commenter does not do this, or is not about, then a community wiki answer is often left. This is a way to use the info from a comment without gaining reputation, so without feeling you are 'stealing' from anyone.

Answer 3

I also often find myself dropping a comment instead of answering. In addition to what was already answered here, my reasons mostly are

Might be too localized. If the answer to a huge question is a one-liner, then more often than not the real problem was a little thing the OP overlooked, having nothing to do with the perceived question at all. In that case, it's often better to close or delete the question, and an answer might be contraproductive.

Not tested / Too little time. When I post an answer, I would at least test it really works, and give an appropriate amount of explanation. When I don't have the time or can't be bothered to test, I often resort to shooting a comment pointing in the intuitively right direction (instead of doing nothing at all). If it happens to hit the point, I can later come back and extend the comment into a "real" answer (if there isn't one already).

Answer 4

Joseph's post speaks about it slightly, but I would like to add one comment. This often happens when there is not enough information in the question, usually because of a missing MWE. This makes the question difficult to answer, so we often just try to guess what is the problem and we shoot a possible solution, as a comment. If later it is found out that the solution was right, it is made an answer so that it can be up-voted, accepted, question resolved.

Answer 5

It may be that people don't consider a one-liner solution to be worth an Answer. There's the feeling that an Answer with capital A is something more detailed. This feeling is (at least in my case) strengthened by the fact that somehow, on this site, there are much more detailed answers than one-liners. The Answerers usually go to great detail even about simple topics because there is the chance that the question poster does not know the correct terminology yet and needs more information.

Answer 6

I sometimes posted advice in a comment, because of being pretty sure that the question has been answered before and I just did not find the duplicate yet. As soon as I would find the duplicate, I would add a link.

It would be good to check for a duplicate at first, before quickly firing answer for rep and badges. I guess commenters often avoid adding an answer to a potential duplicate, or to a very localized question with a small mistake to be corrected.

If a question is likely to be closed, adding a comment may be better than adding an answer (which would conflict with the intention of closing).

If it turns out that it should be a real answer, it's a good etiquette that the commentor makes one, or would be asked so. In case there's not response we often noticed community wiki answers made instead.