I just had an interesting experience, which I think highlights an area where StackExchange could improve the "close as exact duplicate function".

This happened when I wanted to find out if allowing down-votes on comments had been discussed here before. I searched for comments down vote in the search bar up top. The first search result that was actually relevant to my query was for:

Vote down comments

That question was closed as an exact duplicate. So, I followed the duplicate pointer to:

We should be able to vote comments down as well as up

However this one was also closed as an exact duplicate, of:

Allow downvoting comments

If these questions are indeed exact duplicates then, under the principle of a=b=c -> a=c, wouldn't it make more sense (and a better user experience) to link a directly to c instead of forcing the user to follow the entire chain?

Of course, part of this currently relies on power users and moderators to choose c when closing a as a duplicate. But, this could be handled by the StackExchange system directly in a couple of ways:

Upon detection of a duplicate chain being proposed:

  • Suggest: "Did you mean to choose this non-closed post instead?"
  • Transparently and automatically replace the proposed duplicate with the root, non-closed question.

Or, there may be another alternative I'm not thinking of. Still, I really don't see a reason to keep (and leave the potential to enlarge) chains like these.

  • 2
    I like this idea and agree that it is a tad annoying when I find a question closed as a dup and click the link just to find that question is also closed as a dup. An alternative might be to not allow a closed question as the target of a close as dup vote/flag but display an info message suggesting that the user chose the target question of the closed question instead of the closed question as the target of their dup vote/flag.
    – chown
    Aug 4, 2012 at 2:27
  • 2
    My only concern is that commonly the "exact" part isn't always true. It's "a ~= b ~= c" (almost equal to), so if it goes "a ~= b ~= c ~= d ~= e", who knows if a is anything like e.
    – vcsjones
    Aug 4, 2012 at 2:48
  • 2
    I should note that sometimes users agree with A => B, but not B => C, which can be a case of legitimate chaining, especially if B has useful answers.
    – waiwai933
    Aug 4, 2012 at 2:54
  • @vcsjones See jmort's answer for a suggestion that could mitigate this. It was something I thought of also, but figured might be more appropriate for a separate feature request.
    – Iszi
    Aug 4, 2012 at 3:12
  • @waiwai933 Please also see jmort's answer for suggestion of a possible mitigation.
    – Iszi
    Aug 4, 2012 at 3:12
  • Closely related meta.stackexchange.com/questions/135364/… Aug 4, 2012 at 7:22
  • I would, from time to time, on purpose flag a question as a duplicate of a closed-as-duplicate question. I keep it for cases when the question is so much of a duplicate that I want the OP to actually follow a chain of duplicates to feel it.
    – GSerg
    Aug 6, 2012 at 0:00
  • 2
    Can't we just merge them all? Aug 7, 2012 at 19:37
  • 1
    possible duplicate of A duplicate of a duplicate of a duplicate?
    – Pollyanna
    Apr 1, 2014 at 2:24

2 Answers 2


If a closed question is linked to other close questions, it may be helpful to make them all visible at the top of the question, instead of only showing the links from that direct question:

Possible Duplicate:
Homework on StackOverflow

Linked Duplicates:
Should I answer Homework questions?
Downvoted for answering homework!
How do we handle the questions marked homework?
Should we eliminate the homework tag?
Is the homework tag a meta tag?

There was one question someone asked about what to do if he is automatically banned from asking questions. Several close voters referenced the first question that came up in the list as the duplicate, and it happened to be closed. I had to click through three "possible duplicate" links before I reached an open question, and it even had a link to the canonical post. Here is an example.

Displaying the linked duplicates may seem kind of messy, but as Joel Spolsky says, inventory that has costs and little benefit should be processed. In other words, if we see the linked duplicates list growing to an unmanageable state, that just means it's time to clean house and either delete or merge some of them.

Note that the "linked duplicates" list wouldn't show closed references, the placeholders left behind when a migration occurs. Sometimes there is value in leaving those as it does help with search results. We just don't want them appearing in our close vote lists.

  • I really like this idea, and had actually thought of it when writing my original post. However, I didn't want to try putting two feature requests in one post. I really like your point about how this could help highlight areas where old duplicates could/should be deleted or merged. This could even be something to add to /review or one of the moderator tools: A list of threads with more than 5 or so duplicates.
    – Iszi
    Aug 4, 2012 at 16:10
  • @Iszi - Yes! I was even going to add something about giving 10k or 20k users the ability to indicate potential migration paths to make the mods job easier, sort of how flags go through 10k users to help the mod determine what action to take.
    – jmort253
    Aug 4, 2012 at 19:29

I totally understand where you are coming from with this, and in theory it could be implemented so that any intermediate questions that are linked to are eliminated from the chain, but this is overlooking some small subtle points:

  • it assumes that there are no answers of any value in any of the intermediate questions
  • it assumes that the root (original) question has a good definitive answer worth linking to

So this means the process cannot be done automatically, it needs some lovin' from a human.

What really needs to happen here is that first you find a question that has an answer that can be considered canonical, and then either link the duplicates to it directly, or flag them for a tidy up. Sometimes you will find a many times duplicated question that doesn't have a canonical answer yet, in this case several questions could be flagged for merging.

  • +1 for merge. That's ideally the solution. If there are too many closed questions interlinking, just merge them into one and link that to the original close. Also, the auto-close suggest feature for close voters should put the non-merged closes at the top.
    – jmort253
    Aug 4, 2012 at 2:55
  • 1
    Merging is one good option. Also, it's been stated in other threads that it should be general practice to propose the best (most well answered, upvoted, detailed, etc) thread as duplicate when closing a new question. Another way to mitigate any loss you've described is to implement the suggestion in @jmort253's answer.
    – Iszi
    Aug 4, 2012 at 3:04
  • A problem here is that not everyone agrees that the question with the best answer is an exact duplicate. Sometimes it works better to link to a question that looks the most like the new one. Some "popular" questions have tons of dupes!
    – Bo Persson
    Aug 4, 2012 at 8:43
  • @BoPersson For the popular questions with tons of dupes, you could list the first 10 (or less, depending on how the UI guys want to limit it) and then provide a link that says "And n more..." where n, of course, is the number of remaining duplicates not displayed up front. The link would point to a listing of all "exact duplicate" questions connected to the original.
    – Iszi
    Aug 4, 2012 at 16:07

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