In this question, there is an answer which was posted (by me, but that doesn't matter) nearly a month ago.

Today, a user posted new answer which (as far as I can see) is the exact same, just with different wording and formatting. I don't see this answer adding anything new.

What should I do when i see such a duplicate answer? (Not just in the case of this question, but in general.) Should I :

  • Comment?
  • Downvote?
  • Flag for moderator attention?
  • Do nothing?

What should people with moderator priviliges do in such cases?

  • 1
    A duplicate is a duplicate, you need to flag it as such. – EKons Aug 1 '16 at 19:05
  • @ΈρικΚωνσταντόπουλος "Duplicate" is not one of the options when flagging answers. Which option should be used? "In need of moderator attention"? – Fiksdal Aug 1 '16 at 19:08
  • 2
    After you've kindly commented, and no action seems to be taken, you need to flag it as "in need of moderator intervention", since there is no "duplicate" option that desparately needs to be added for the whole Stack Exchange network because this network is not a forum, dupes are bad! – EKons Aug 1 '16 at 19:11
  • @ΈρικΚωνσταντόπουλος Thanks for your response. I think it's worthy of being an answer rather than a comment. – Fiksdal Aug 1 '16 at 19:13
  • No, it fits as a comment here. The answer I was about to give is alerady in. I upvoted it instead of writing a new answer. – EKons Aug 1 '16 at 19:14
  • @ΈρικΚωνσταντόπουλος While is certainly up to you whether you make it an answer, the current answer says to flag only exact (copy-pasted) duplicates. When an answer has the same content worded differently, it suggests to just comment. Anyway, not saying you should answer, the comment is fine too. – Fiksdal Aug 1 '16 at 19:18
  • 1
    I think I read it differently the first time. – EKons Aug 2 '16 at 8:47

I can't answer for every moderator, and the closest thing I found to an official policy is this question on meta.SE, but I can tell you my perspective.

In the case you describe, where a user has written a new answer that isn't the exact same text as an old one but has the same information, typically I'll leave a comment telling the new user that their answer doesn't add anything new, and hinting that it would be better to spend their time on unanswered questions. If there's any possibility the new answer might be useful as a complement to the old one (e.g. it explains things differently, some users might find the new answer clearer, it's updated for a newer version), then I'll leave the answer in place. If it adds nothing at all, I'll usually delete the new answer: not to punish the answerer, but just to keep the site tidy, and to reinforce the message that we're not interested in duplicate content.

As a non-moderator, you can add such a comment yourself, but please make sure to keep it encouraging. The new user is probably used to a forum site where you have to repeat replies to show that you agree with them, instead of being able to upvote. They spent their time writing the duplicate answer because they wanted to help, so complaining at them can feel very negative even if it doesn't seem that way to you. Make sure to say that there's no need to write a new answer, rather than that it's "wrong". Tell them that answering unanswered questions is more helpful. Welcome them to the site and thank them for contributing.

If that all sounds like a lot of work, there's no need for you to do anything. Having the duplicate answer doesn't really harm the site, it just makes it a little harder for the best answer to "rise to the top" with upvotes. If you want to add a custom flag to the answer to let the moderators know, feel free, but the outcome will probably depend on which moderator happens to look at the flag. :-)

There's another case, which is when a user posts the same exact text as another answer, either by the same or a different user, on the same or a different question. Please always flag these. We'll typically delete the duplicate and tell the poster why, but sometimes the situation is more complex and requires more effort. Sometimes it's a mistake, and the duplicate should have been an edit; sometimes it's plagiarism; sometimes it's an honest attempt to help, but it lets us know that there were duplicate questions that should have been closed. The system does quite a good job of detecting them, but some duplicates slip through. Typically I'll always mark those flags as helpful, even if I end up taking no action.

  • 1
    Thanks for this, and also for the reminder to be friendly to new users. – Fiksdal Jul 19 '16 at 10:44
  • 2
    Don't forget the 3rd case, when the new Q/A "supersedes" the older one remarkably. We've had cases where we've closed the older one as dupe to the new one (ask Matthew, he should remember). And case number 4 (rarely happened) might even result in the two being merged :) +1 meanwhile :) – Izzy Mod Jul 19 '16 at 12:47
  • 2
    I would also suggest that an answer that doesn't add anything new that the other answer(s) didn't cover is the very definition of "not useful" and should be downvoted. – ale Jul 27 '16 at 14:00
  • 1
    @Izzy Why can't just merge every duplicate? – EKons Aug 1 '16 at 19:08
  • @AlE. Maybe you could add this as an answer rather than a comment? That way we could vote on it. – Fiksdal Aug 1 '16 at 19:14
  • @ΈρικΚωνσταντόπουλος Multiple reasons: 1. it's a tough job :) 2. "SEO" (people finding their way via duplicates, so we leave them as signpost) 3. Some Dupes are not worth it :) – Izzy Mod Aug 1 '16 at 19:27
  • @Izzy Are you discussing duplicate answers or duplicate questions? – Fiksdal Aug 2 '16 at 8:53
  • @ΈρικΚωνσταντόπουλος Are you discussing duplicate answers or duplicate questions? – Fiksdal Aug 2 '16 at 8:53
  • 1
    @Fiksdal Good point – so I must add 4.: You can't merge answers :) – Izzy Mod Aug 2 '16 at 8:55
  • @Fiksdal Dan Hulme mentioned merging, you should ask him instead ^(^_^)^ – EKons Aug 2 '16 at 9:15
  • @ΈρικΚωνσταντόπουλος I meant when you said "Why can't just merge every duplicate?". And it was actually Izzy and you who were talking about merging, Dan Hulme didn't mention it. – Fiksdal Aug 2 '16 at 9:19

What is a duplicate answer?

A duplicate answer is an answer that does not add any information not alerady in an older answer.

What should I do about that?

  1. Be sure to be on the duplicate answer, not the original one.
  2. Leave a comment kindly saying that the answer doesn't add anything new to the question, and thus should be appropriately edited or deleted.
  3. Expect the following.
    • A reply within a short time (I would recommend 18-24 hours).
    • An appropriate edit or deletion (I would recommend 18-24 hours).
  4. If you got a reply, expect an appropriate deletion or edit within a short period (I would recommend 2-30 minutes).
  5. Flag the answer as "in need of moderator intervention". In the reason box, type the following:
    1. "Duplicate of "
    2. [link of original answer]
    3. "."

Note that the above text is only an example, but you need to provide the link to the original answer, if you want quicker mod action and/or don't want mods to search for a possibly long time to find the original answer because they have to do other things too and you are uselessly delaying them with that.

You said I need the link of the answer, but how do I obtain it?

At the bottom of every answer, just above the comment section, there are at least these 3 buttons: "share", "edit" and "flag" (if this isn't there you couldn't flag in the first place.)

  1. Be sure to be on the original, non-duplicate answer.
  2. Click on the "share" button
  3. Copy the link from the white text box that appears

Then, go to the duplicate answer and do step 5 (or 5.2, if you managed to keep the flag window open all that time).

What if the duplicate answer is posted much later than the original one?

A duplicate answer is a duplicate, no matter when it is posted. It just needs to be posted at least 1 second later than the original one in order to be recognizable as a duplicate.

What are other cases of this problem?

  • Two answers are posted the same second; one is a duplicate of the other. What should I do?
    • This is another story.
  • An answer is a duplicate of more than one other answers; what should I do?
    • This is another story.
  • An answer is posted on a duplicate of this question, and doesn't add anything new to the original question.
    • This is another story.

You must log in to answer this question.

Not the answer you're looking for? Browse other questions tagged .