Should we be using comments as substitutes for answers?

Question

I've been noticing that this site has been using comments as substitutes for answers in quite a few questions. Examples: 1, 2. I've probably done this a few times myself.

I think one explanation that I've seen is that the person commenting doesn't have time to do research and write a detailed, backed up answer, but they still want to provide an answer to tide the OP over.

The problem is that the official documentation is pretty clear about what comments should be used for:

When should I comment?

You should submit a comment if you want to:

• Request clarification from the author;
• Leave constructive criticism that guides the author in improving the post;
• Add relevant but minor or transient information to a post (e.g. a link to a related question, or an alert to the author that the question has been updated).

When shouldn't I comment?

Comments are not recommended for any of the following:

• Suggesting corrections that don't fundamentally change the meaning of the post; instead, make or suggest an edit;

• Answering a question or providing an alternate solution to an existing answer; instead, post an actual answer (or edit to expand an existing one);

• Compliments which do not add new information ("+1, great answer!"); instead, up-vote it and pay it forward;

• Criticisms which do not add anything constructive ("-1, see previous comments you scallywag!"); instead, down-vote (and provide or up-vote a better answer if appropriate);

• Secondary discussion or debating a controversial point; please use chat instead;

• Discussion of community behavior or site policies; please use meta instead.

Should we be using comments as a substitute for answers?

Answer 1

In the spirit of not leaving answers as comments, I've converted BESW's insightful comments on this issue into an answer.

Comment answers can't be searched, so their usefulness as content on a site dedicated to providing answers for later users is barely noticeable. They're also used to bypass question holds and thus pull the teeth from our most important tool for optimizing for pearls: comment answers reduce community interest in improving closed questions to get them re-opened (since they already got an answer without any extra effort needed).

And they're broken windows that encourage other, even less productive use of comments (like arguing, or avoiding using meta). Personally I've found that a Stack's attitude toward comment answers is a good gauge for its overall attitude toward quality, rigor, and general niceness.

I challenge the idea that answers-as-comments contain meaningfully useful information: the information in a comment is not accessible according to site standards and is only useful inasmuch as it gets moved into a full answer. The benefit is minuscule, because the transition from a comment to an answer is so rare, and is far outweighed by the quality reduction associated with the cultural problems that comment-as-answer permissiveness encourages.

Asking people to turn comments into answers doesn't work. I've seen it tried on far too many sites, and people who leave comments as answers did it because they don't want to (or think they can't) turn it into a full answer. (Consider this a sign of the low quality of comment-answer content, btw.) Turning someone else's comment into an answer yourself is better for the site, but still doesn't do anything to discourage the comment culture: in fact, it validates the notion that we should leave incomplete answers and expect others to do the hard work.

Let's remove these comments as answers, and move on to other, more useful forms of participation instead.

Answer 2

Technically, you're right: comments are supposed to be used for feedback on the question, not for suggesting answers. And I know some SE sites take a hard line on 'answers as comments' and tend to delete them on sight, directing the commenters to the answer box instead.

But this is one of those network-wide 'policies' which is more than a little malleable from site to site, and I suggest that we discourage but not delete answer-like comments.

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Why not to delete them?

• Deleting them would be removing potentially useful content from the site at very little gain. Surely removing helpful content goes against what SE is supposed to be all about.
• Not deleting them enables us to ping the commenters suggesting they leave an answer instead, and enables them to come back and find the info later to jump-start their answer. So by not deleting such comments, we actually increase the chance of them turning into answers.
• Often what would be a bad answer is still a useful comment: e.g. an unelaborated link to a source of further reading, or an unsupported possible explanation of the issue being asked about.

A common issue on SE is the occasional disconnect between following the letter of the law and using common sense to do what's actually most useful in practice. I've seen various places where people were calling for some action on the grounds of a literal interpretation of something in the help centre, and had to be told e.g. "if it's not causing any problems for the site, don't worry about it" or "look at the big picture of what we're all actually here for, rather than focusing on one particular aspect of one particular policy". This, in my view, is one of those cases: we shouldn't be removing useful information from the site if it's not causing any problems.

Counterarguments would be that comments can't be downvoted (but the voting on answers here isn't always reflective of quality anyway) and that we really need more answers (but deleting answers-as-comments wouldn't achieve that, and in fact would probably be counterproductive for the reasons in the 2nd bullet point above).

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How to combat them?

Of course, this isn't to say that we should welcome or encourage people posting answers as comments. As mentioned above, we should respond to such comments asking the commenter to turn them into an answer. If they don't want to or don't respond for a long time, then it might be acceptable to turn someone else's comment into an answer yourself, preferably with attribution to them for the original idea. Depending on how much extra work you put into the answer compared to the original comment, you might want to make it CW, but there's never any obligation to do so.

I've done this a few times here on Lit. Usually I try to put some more effort/research into the answer, so that I don't feel like I'm simply stealing someone else's response. Sometimes the original comment is deleted (probably by the commenter themselves) after the answer is posted.