Should "this is what I did" be updates to the question or stand alone answers?

Question

We get some people who will return to their asked question to post "this is what I ended up doing". Some update their original question, some post it as an answer.

When I see it as an update to the original question, I've always posted a comment thanking them for the update, then asking them to make an answer out of it, since "this is what I did" seems like an answer to "how do I do this".

This question is a prime example of the genre. However, as of this moment, this is the very next question in the queue, and our esteemed moderator Niall C.♦ has, in just the last few hours, deleted the self-answer by the OP and made it an update to the original question. Granted, in this case, the OP did ask an additional question in his answer (which should, of course, be a new question).

It, obviously, seems to me that the "this is what I did" update is actually answering the question and should stand alone as an answer. However, that's been countermanded by a mod who, I presume, knows the SE and community rules better than I.

My question is which is the preferred or official method of dealing with a "completion" update from an OP?

I don't think we'd want to discourage people providing updates, as they do provide closure and it does help others to know what someone else actually did with this information.

Answer 1

That post came to my attention via a "not an answer" flag from another user. I agreed with the flag because the question the OP actually asked was:

Is there a problem with using 18/2 wire with the 220 volt system in the UK?

Their subsequent post doesn't actually say whether or not it's OK, it's describing the specific wire they just bought.

Other things I picked up from the post:

• the "Thanks for the thoughtful responses" at the start of the post. This is something we frequently see in follow-on posts from new users that don't realize they can edit their posts with additional information.

• the "Is that the difference? I want to be safe." at the end, which sounds like they haven't actually solved the problem yet, but this what they're thinking of using and want confirmation that it's OK to do so.

Answer 2

My question is which is the preferred or official method of dealing with a "completion" update from an OP?

If OP has a solution they want to share, they need to post it as an answer. If it's the solution they ended up using, then they should also accept that answer. That's exactly how the Stack Exchange Q&A system is intended to work: questions/problems belong in questions, and answers/solutions belong in answers.

If they don't do this, you can comment and recommend they take that course of action. If it's been a while since commenting (or if they haven't been active for years), you can edit the question yourself to remove the solution and then post it as a Community Wiki answer with a subscript indicating that the solution is from OP. I do this all the time on Stack Overflow. Some of the time those answers even get accepted by OP later on when they come back to the site.