Merge answers but not question when closing as duplicate

Question

It frequently happens across all SE sites that duplicate questions garner a few answers before they get closed. Sure there should be a policy about not answering dupes, but only the high rep users are likely to know when something is heading towards closure.

• Some users don't realize the question is a duplicate and make their best effort to answer.
• Some are looking for some quick free rep.
• Sometimes recognizing duplicates and closing them can take a lot of time.

But never-mind the reason. The fact is sometimes valuable answers show up on questions before they get closed as dupes.

These answers are frustrating for a couple of reasons. Often the answers to the original question are more mature, but because answers show on the duplicate they often get looked at and even voted on. The rep trolls get fed and answers aren't fairly voted on against each other, only against a subset still showing on the dupe.

Sometimes the reverse happens. A better answer will turn up on the new question that isn't in the old question. This happened to me today when I wrote up a thorough answer to a new question, then later found that I'd answered the same question some months back with a two liner. I voted to close the question, leaving MY answer as the one locked on the closed question. I opted to delete it and edit my old answer, but gave up the rep from my better answer before the question got closed. This made me realize the toolset could be improved.

I propose...

...that when a question is closed as a duplicate, the default behavior should be the assist in migrating the answers to the new question to the old one. If the question is truly a duplicate, answers should be mergeable. There is value in leaving a duplicate question to be found by future users that search the specific wording, but there does not seem to be value in leaving answers hanging around on closed question that should be found under the duplicates.

• Answers merged from recently closed questions will be at a time disadvantage compared to old ones, but this is fair. If they are duplicate answers they will float to the bottom. If they are better they will get voted up.
• Rep trolls will go that much hungrier.
• Better answers won't be in the awkward position of being locked.

Additionally answer posters could be prompted for how to handle their own answers to anything that is closed as duplicate. These prompts could include:

• Migrate to original question?
• Edit and migrate?
• Delete?
• Convert to comment?

In the end, questions closed as duplicates should not have answers floating around on them. Right now they do, all over all the sites. I realize there is some kind of merge function available to moderators, but the majority of questions aren't handled that way they are closed by votes and any answers posted before the close generally stay put.

Answer 1

"but there does not seem to be value in leaving answers hanging around on closed question that should be found under the duplicates."

The problem with duplicates is that whilst both questions (original and duplicate) can be about how to do X with Y, the wording of the questions can be very different and the OP's source code examples, if supplied, can differ wildly.

If a yet-to-be-closed duplicate question has started to accrete answers where they quote the OP's source code (or OP specific terminology etc) then it's not possible to merge these into another question because they'd be completely out of context.

Merging duplicate questions and answers only works where both questions are absolutely EXACT duplicates.

The present system works reasonably well, and there are some gems of answers in questions that have been closed as duplicate that are sometimes a lot better than answers in the post that the question is being closed as a duplicate of. Unfortunately, without a serious amount of editing of both the original "canonical" question and the dupe's answers, which is often not practical, merging isn't the correct solution.

Answer 2

In response to feedback an in light of other issues (such as how to reward the finding of duplicates) I think another change could accompany an answer merge function.

If merging answers was the responsibility of people that answered a questoin before it was closed as a duplicate, we could have votes on answers to closed questions not count for any rep, but with the option to migrate the answer to the open version of the question, the votes and rep would come with it. This would discourage people trying to collect rep on questions that they know will be closed as duplicates and to answer in light of the original question instead.

Removing voting on answers to closed questions entirly would not be a solution because wrong answers should still be downvoted so as not to mislead folks and good ones should still be brought to the top, but the priority should be on getting any relavant, good ansewers to the open question.

Answer 3

I have recently been thinking about this feature request and think it is a valuable idea to look at again.

The purpose of marking questions as duplicates is so that there is a canonical reference to that particular question. But if there are useful, correct answers associated to duplicates then these are not canonical themselves so are effectively lost. With duplicate questions we're only serving to discourage people from re-asking the same question, and not really helping them to find the answer.

Proposal

I propose that when questions are marked as duplicates that there should be a dual-option - 'mark as duplicate', and 'mark as duplicate and merge answers', and introduce in a new review queue to handle these merged answers.

If the duplicate+merge is agreed then the answers can be added to a new review queue - Merged Answers. Then reviewers can review these answers to see if they are appropriate answers for the original post and then approve / decline as appropriate. Any answer reviewed positively can then be added to the original question. Any answer that is reviewed negatively can remain on the old, closed question.