I feel like we got off on the wrong foot. Due to me being an idiot miscommunication, a partial change snuck out early, and even though we announced it we didn't really explain why we made the change. So let me just start over...
We've made some changes to Close as Duplicate.
First, some background: we're taking a look at closing behavior and trying to figure out how to make it less jarring for new users. Our goals are (1) to make it clear to people why their question got closed and (2) to make it obvious what they can do to fix it or get better (3) in order to reduce the likelihood of getting into an argument about whether this should have been closed.
We started with dupes. The old close reason looked like this:
Closed as Exact Duplicate by David Fullerton♦ 1 min ago
This question covers exactly the same content as earlier questions on this topic; its answers may be merged with another identical question.
That's okay as instructions to the person voting to close, but it doesn't tell the user anything. Worse, it sounds a bit like those old forum stickies that said “PLEASE SEARCH BEFORE POSTING YOUR QUESTION” – somebody already asked this exact same thing, so please stop bothering us. It's strong wording practically invites the user to argue: "My question is not identical! I used different words!"
So what do we want to tell the user instead? Something like, “Somebody already asked this. If that other question doesn't solve your problem, please clarify your question to explain how it's different.” Perfect: if the other question helps them, they're happy because they got an answer. If the other question doesn't help them, they know exactly what to do. No argument about how exact an "exact duplicate" needs to be.
Now, notice that this is subtly different from saying "If that other question isn't asking the exact same thing as yours..." That's because the proof is in the answers. If the question looks the same, but the answers aren't solving the asker's problem, that is not a dupe – that is a legitimate new question. Neither the person asking nor the person who lands from Google cares if the question has been asked before: they care if it has been answered.
So here are the changes we made:
We've changed the instructions everywhere to indicate that the answers to the original question must solve the dupe’s problem. That means that the original must have an answer †
When a question gets closed as dupe, instead of just saying "Possible duplicate", we now indicate "This question already has an answer here".
If the owner comes back and edits their closed question, it will automatically go into a reopen queue. There's even special UI to compare before and after and see what changed.
The "Close-as-dupe" popup now makes it much easier to find dupes with answers by allowing you to search and preview questions and answers within the popup.
We now show "[duplicate]" in the question title everywhere, instead of "[closed]".
† There are some exceptions to the requirement that the original have answers. First, mods can close as dupe of anything, to handle any special cases. Second, you can always close as dupe if it's from the same user, to cover the case of problem users who post the same thing multiple times. Last but not least, this check is disabled on meta.
Here's an example duplicate post so you can see all the changes together: Is there a way to know proximity of getting banned?
Based on our queries, about 2% of questions didn't meet our new criteria when they were closed as dupe. Some of those are because they were closed as dupe of a dupe, which is something we shouldn't be doing anyway. Others are because the question actually has been asked before, but nobody has answered it yet. I think we can live with that, because maybe this is the one that will finally have the information / keywords / whatever it needs to get answered.
The fundamental goal of dupes is to help people find the right answer by getting all of the answers in one place. It is not to just clean up clutter. Dupes are okay. We love (some) dupes. There are many ways to ask the same question, and a user might not be able to find the answer if they're asking it a different way. We think these changes maintain the goal of dupes and result in a much better experience for the asker and the Googler who just want to find an answer.
With that said, this is still experimental -- if it's breaking the site we can always remove the requirement for an answer. Now that this is live, we're especially interested in examples of things you'd like to close as dupe but can't now.
Part of the close reason rework project: