Please do not answer a question in a comment

Question

From our help section on the comment privilege:

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).

and

Comments are not recommended for any of the following:

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

Nevertheless, instead of writing an answer people increasingly write a short comment only. These comments range form being a full answer of the question to a partial answer, or a link that answers the questions.

This is bad for the site as

1. These comments cannot be downvoted. There is no community control to judge the value of any such comment.
2. Whenever there is a comment that answers the question, people are reluctant to write an answer when it would have the same content.

We therefore will delete any such comment without mercy and irrespective of the value it may have.

If you come across any such comment please take the valuable information from it and copy & paste it in an answer. You can also post an answer to your own question this way. Then please flag the comment as no longer needed to bring it to our attention for deletion. Of course you may extend this answer if needed but even a short answer is better than none.

Thank you.

Answer 1

We therefore will delete any such comment without mercy and irrespective of the value it may have.

In my opinion, mods should enforce this policy. At the moment, they do not seem to be doing this.

Answering questions in a comment is bad for at least the reasons outlined in the original post: it discourages actual answers, and there is no quality control (in the form of edits, downvotes or retractions of upvotes). It goes directly against the stated purpose of comments (to improve or clarify questions and answers) and undermines the question and answer format of the site.

The deletion of such comments should not be understood as censorship or censure. The same content would not be deleted if it was delivered in the appropriate form, i.e. as an answer.

Finally, I oppose placing the burden of maintaining site policy on other users. These comments should not be required to be flagged before being removed, nor should it be necessary to always ask the posters of such comments to repost their comment as an answer.

_{As an afterthought: One aspect I find personally annoying about answers in comments is that I feel they are diminishing the question. In a sense, they are saying that the answer to a question is so obvious that it is not even worth the time of writing a proper answer. In my view, one thing that makes this site attractive is the ability of some posters to write highly enlightening answers to seemingly trivial questions.}

Answer 2

@Wrzlprmft: Thanks for the link to this question. I had already seen this and prepared a comment, that I lost.

I don't deny the rational, but I object that the three guidelines "When should I ..." are helpful. They can all apply, if the following is implied when answering a question in a comment

"... is this what you wanted to know or how specific do you need it" (clarification)

"... This is an easy answer that you should be able to find yourself" (criticism)

"... this is not a full answer, but the gist is ..." (transient information)

In that light the rules are inconsistent. Ex contradictione quod libet. You are left to exercise your own judgment.

The rational given in the above question slash assertion concerns first the lack of downvotes for comments, and second the detriment to other posters answers.

The former can be criticized variously, e.g. because a single up or down-vote does not have a lot explanatory power and a responding comment would be appreciated instead, which those who down-vote often don't write when actually down-voting an answer. So it's only half a solution.

Of course there are more reasons besides that. Answering a low effort, off-topic or otherwise ineligible question motivates more of the same kind, so these shouldn't be answered at all. However, as a matter of good measure, a few such answers to leave nobody hanging won't doom the site. There's the saying about teaching man to fish, but if you try to teach fishing with a heavy handed hammer, you are doing something wrong.

As LangLangC's answer shows, elaborate answers have a tendency of running on for a while. Some of them never get to the point, and the fact is lost in the noise. If the supposed answer fits into a 512 character comment instead, the value of some very context specific questions that can be phrased in thousand different ways is doubtful anyway. So I'd say we have different problems to care about.

A comment answer is indistinguishable from other comments, so it's not equivalent to an answer that sits at 0 votes, but basically, that's what it should be. And nobody should really have a problem with those. As others noted, an answer bumps the Q, gives +points for the askee when accepting the answer, and it might give -points for answers to a low effort Q. Refer back to the above argument about the subjectivity of votes. Different votes have different reasons, and some reasons may be deemed less valid. After all, it's lucky that down-votes are scored disproportionately to up-votes. So yeah, don't answer in comments.

It's not true that the practice has been increasing, though. It has always been done, and is unlikely to stop now.