One of those topics occasionally bantered about in chat, and with a bit more frequency lately is about how we close with duplicates and what these questions should be.

The idealized flow with closing for a duplicate is one of:

a1. Vote to close as a duplicate

and then either:

b2. Poster rewords question to address the "not a duplicate nature"
b3. Revised question is a good one, reopened, and life continues


c2. Poster says "yep, that is it" (or sufficient other voters agree)
c3. Remaining question is either good (as a sign post for future) or poor (and eventually deleted)

The post is correctly closed as a duplicate path (c)

There is no problem with the 'c' path other than the possibility of eventually cluttering up the linked questions with duplicates that aren't good sign posts. For an example of this see the 2,200 posts linked to Stack Overflow's NullPointerException question - that really doesn't help anyone. And while we don't have 2k NPE questions here, having 20 or so questions linked to a post diminishes its value unless those are good questions to begin with.

One can see the most linked questions with this data.se query along with some other statistics. Our most duplicated questions often have long discussions and lots of views.

Closing as a duplicate of these locked or closed questions says "we once accepted this, but we don't any more" which indirectly leads to further confusion of scope (that these discussions, debates, holy wars, polls are appropriate here), too broad, etc... and misplaced nostalgia back to earlier times.

My opinion: A duplicate vote implies that this is also a discussion and... well, my take is that aren't good posts in the first place (especially if one looks at sorting by AnswerCount). Interesting, yes... but these are blog posts and reddit threads instead. Maintaining these massive answer collections makes it harder to say 'this isn't a good question.' and provide appealing targets for discussion targets that are tangentially related.

When the close vote is a stretch (a)

One problem occurs when a1 is a stretch - that it is an "this post addresses the question." This is contentious because if the "this addresses the question" is the threshold for an answer on a question, then posting an answer from the other question as is would be a viable answer... which is one of the criteria for determining if one would vote to close the question as a duplicate.

However, the other criteria for a close vote as a duplicate is that it asks the exact same question.

And thus, one of the two sets of statements here should be considered proper

  • An answer should answer the question, not just address the question
  • A duplicate post must be an exact duplicate, so that the answers on the duplicate target exactly answer the question here. A duplicate question should be a strong candidate for merging.


  • An answer should address the question, but does not need to answer it fully
  • A duplicate post must lead the asker of the question in the proper direction to solve their problem. A duplicate question is a sign post on the road to understanding the entire picture.

When the (revised) question isn't good (b')

Not a good question in the first place (b2')

The other problem with this is when the question itself is really unclear, too broad, or primarily opinion.

We've effectively done that with writing a specific off topic reason with "we won't debug your code" rather than writing a canonical duplicate that such questions get (unhelpfully?) duplicated to. The off topic clearly indicates that we will not answer those questions here. The duplicate... not so clearly.

While we might find that duplicating the question to another one that was asked that is the correct duplicate, it leaves poor questions in its place... and it also makes the duplicate target that much harder to remove in the future.

Not a not so good, but clearly not duplicate (b3')

There is also the situation where a question is modified to be clearly not a duplicate, but still isn't a good question. With the number of close voters that are active on the site, this poses a special problem for trying to close questions and keep poorly written ones closed.

When the question isn't a duplicate, they do get reopened - even if they aren't good questions. And as the duplicate took five votes to close, it takes another five votes to close again from other users. This may mean the question never gets closed a second time, leaving poorly asked and written questions open on the site.

Unfortunately, this situation is often the case on Programmers.SE - a question is closed as a duplicate of another opinion or too broad question, addresses the "this is not a duplicate" but remains a question that is primarily opinion, too broad, or is still unclear.

The resulting situation isn't good - the original post (if it remains closed) is no longer a duplicate of the target dup (bad for future readers). Alternatively, if it is reopened, it remains a not-good question.

And so, the best case for this is possibly pretend the other question doesn't exist when closing a question that isn't a good fit in the first place, especially in situations where one would be casting a down or delete vote on the question anyways - it isn't a good sign post and will ultimately be deleted.

  • Close with the 'real' reason: opinion, too broad, or unclear
  • Make mention of the related question in comments

While this may hinder our SEO, it presents a better appearance to the random person coming from google. It also means that more questions (and answers) that are not good fits for the Stack Exchange Q&A format are likely to end up deleted.

The guidelines for this would be:

  • Don't duplicate to a question that should be deleted
  • Don't duplicate a question that should be deleted

This should also include a critical look at the questions that we are closing as a duplicate of and consider if these are things that we want on the site and delete them too. I will also point out that historical locking them makes it harder to justify not closing these questions as a duplicate of the historical lock as the historical lock contains the text that this is not a good question for the site and they are difficult to search otherwise that duplicate votes to historically locked questions are less likely to be spurious.

There's another wrinkle into this. While Programmers.SE doesn't have any yet, gold tag badge holders can close as a duplicate with a single vote. This is very useful on other sites as it reduces the necessary votes to close a question. However, this is sometimes used as a "I can either close as a spurious duplicate now or I can cast a too broad, wait two hours and hope that it gets closed before anyone gives an answer."

That hope for the "no one answers" is often in vain. This results in ultimately deleting the question, reputation loss for people who answered, and an increased unease with the Stack Exchange Q&A platform.

However, that is the tool and in the face of "close it fast or create worse experiences for more users" the close it fast may be the right answer, however wrong it is. At least under the current system.

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    This needs a tl;dr.
    – yannis
    Commented Dec 10, 2015 at 20:40
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    @Yannis «if we want fewer dups to tangential discussions, IMHO: get rid of those discussions of old.» and «If it is valid to post an answer with something that addresses the question rather than fully answering it, then a duplicate vote to another post that addresses the question isn't out of line.» and then there is «don't cast a duplicate vote on a crap post in the first place.»
    – user40980
    Commented Dec 10, 2015 at 20:43
  • "Closing as a duplicate of these locked or closed questions..." Eh? Most of the questions in your query are perfectly on topic. I don't see what's the problem there. Sure, some are not, but... who cares? Why is 10, 20, or even 30 closed dupe targets an issue? The site survived having thousands of open absolutely crappy questions, it can certainly survive 30 closed but good questions.
    – yannis
    Commented Dec 10, 2015 at 20:51
  • «One problem occurs when a1 is a stretch - that it is an "this post addresses the question." This is contentious because if the "this addresses the question" is the threshold for an answer on a question...» Please explain why this is contentious. In all my time on the site I have only seen one user routinely suggesting duplicates that aren't exact(ish) duplicates. Everyone else seems perfectly fine only voting to dupe exact dupes.
    – yannis
    Commented Dec 10, 2015 at 20:58
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    @Yannis The query returns back all 1885 duplicate targets. Yes, most are on topic. However if we want people to stop casting duplicate votes to, say How Can I Know Whether I Am a Good Programmer? (14 duplicates), or How do you dive into large code bases? (46 duplicates) or Are certifications worth it? (27 duplicates) consider if those are good questions to have on the site in the first place.
    – user40980
    Commented Dec 10, 2015 at 20:58
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    @Yannis the critical part there is if the duplicate vote was sufficient to get the OP to change the question to say that it isn't a duplicate by adding relevant information. Part of the issue is that it is easier for close votes to go "dup -> reopen -> too broad" than "too broad -> reopen -> dup". The later requires a significantly more determined set of close voters because people who are likely to suggest the duplicate are likely to be on the first round of close voting. There is also the bit that dups take fewer close votes (OP community close) when it is right.
    – user40980
    Commented Dec 10, 2015 at 21:08
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    Honestly, no. We - as a site - have absolutely no problem closing questions. The "too broad -> reopen -> dup" route is as easy as any other.
    – yannis
    Commented Dec 10, 2015 at 21:10
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    ... and as long as there is a scarcity of close votes on the site, it is easier to close as a duplicate than it is to reclose as a duplicate. Between gold badge (not yet here, but some day...), Community♦ OP close - dup votes are cheaper to cast. And its hard to do the "close as too broad, reopen, and then get it closed as a duplicate". Maybe if mods where more active in closing too broad questions up front... but that gets into other issues. For the community to close questions, this is the path of least resistance and most utility - and that is a problem.
    – user40980
    Commented Dec 10, 2015 at 21:11
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    "scarcity of close votes" Erm, this hasn't been true for years.
    – yannis
    Commented Dec 10, 2015 at 21:12
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    @Yannis It is very hard to find the second set of five close votes for the past year or so.
    – user40980
    Commented Dec 10, 2015 at 21:13
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    I don't see why that's a problem. If there's a problem there then that's needing a second set in the first place. The whole path of least resistance is nonsense. Either vote to close honestly, or don't. If you are unsure, just move on, someone else will take care of the question. Intentionally picking a close reason that doesn't quite fit is just asking for troubles.
    – yannis
    Commented Dec 10, 2015 at 21:22
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    "Don't duplicate to a question that should be deleted. Don't duplicate a question that should be deleted." This. A thousand times this.
    – yannis
    Commented Dec 10, 2015 at 21:26
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    If a question is too broad, close as too broad. Closing as a dupe assumes that the OP will come back and actually fix both issues (broadness and duplication). Do we have more than a handful of examples of that happening in all the site's history? Just close as too broad and post a comment with the potential dupes. If the OP fixes the question but ignores the dupes, then refuse to vote to re-open. Problem solved.
    – yannis
    Commented Dec 10, 2015 at 21:32
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    If you know it's rare, why propose a workflow that only works if people fix their own posts? It may be a tad more common for duplicates, but it's still rare.
    – yannis
    Commented Dec 10, 2015 at 21:44
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    @Yannis as to the "less closing" I will return to the "grab the last 24 or 48h of closed questions list them out in a meta post and have a discussion about which ones should be reopened (or left open) or are borderline." However, every time I've done this in the past and actually look at the list I find it really difficult to say "that post should have been left open." Beyond that, I find it difficult to give any credibility on the "we should be closing less" idea... I would like to flip it around to "we should be getting better questions asked." but I have little if any control over that.
    – user40980
    Commented Dec 10, 2015 at 21:48

2 Answers 2


Seeing as our dupe-closure practices are something I've complained about ad nauseum; I suppose I should pipe in here.

To be sure, a bit of your question is not super clear to me after reading it through... It appears there's a couple things you advocate for and a couple things you're questioning and trying to lay out choices for.

I'm basically going to ignore all of that (Who's surprised?) except for the one point which I think we all have broad agreement on - and is just something that perhaps people needs to be more cognizant of:

  • Don't duplicate to a question that should be deleted
  • Don't duplicate a question that should be deleted

I would say if a question should be closed for any reason other than duplicate, it should neither be a duplicate target, nor a duplicate closure. Deleted isn't the relevant discriminator here; just acceptability as an open question is what matters.

That said I would like to lay out what I believe is reasonable usage of the duplicate vote, and discern my reasoning for and against certain practices.

The basis for my entire perspective on dupe votes is: What makes the site the highest quality and most useful catalog of content to future consumers possible?

I grant that my opinion of what does this is just mine and would be happy to find evidence or hear arguments that refute it so that I may be corrected in this. That said, my opinion of the experience for a duplicate goes about like this from a user perspective:

  1. Google problem or question you have
  2. Find question asking about the exact same thing you are wondering- your exact scenario playing out for someone else previously, sweet surrender you've found it!
  3. This question has been closed as a duplicate without a good answer- so you follow the duplicate link.
  4. The question linked is not the exact same problem, similar perhaps, related even, but not the same. It had 3 answers and none of them fit to your specific scenario like the first one did.
  5. You feel betrayed by coming so close to a solution to your problem, only for it to have been cut-short and replaced by non-solutions.

I would say, the majority of people who run into a duplicate closure are getting exactly this experience. This is true largely because there have been so many duplicate closures done just because it's easier / "nicer" than a real closure, or because the question is on-the-fence topically/quality wise so none of the normal closure reasons fit- but people feel it should be closed and thus abuse the duplicate reason.

There are variations on this scenario that occur, occasionally the duplicate question is different but still answers the question they had, and more rarely the duplicate question is the exact same question and answers the question. I would say that exact duplicates are in my experience rather uncommon as google tends to be people's first tool, and if we have their exact scenario it's usually found easily and quickly. Color me wrong on that note if that's what I am; this is just based on my anecdotal experience.

When you put it all together and think about what we're providing to users experience wise - what can we do to improve it? Step one is as mentioned previously, obviously close questions that should be closed - and regard dupe as something different than closing (because that's how visitors will regard it). In simple terms, don't dupe to junk and don't dupe from junk.

After we've tackled that, the next thing to look at is duplicating things to questions that aren't exactly the same.

When a similar question has an answer which you think answers this question

Some people say if the question has an answer which is correct for the not-quite-the-same-question, then you should dupe vote it. I tend to disagree here because with enough dupe votes, you're effectively having community agreement as to what is the questions answer rather than allowing the user to accept an answer. This is not the site's intended functionality, only the asker can truly claim whether an answer solves their problem. In this case I would suggest that users post comments suggesting the answer they think solves it; if the asker declares it does answer their question then a dupe vote makes sense perhaps.

However, when a group of community members get together and decide what the answer to someone's question is, when they're wrong it both stops the user from getting the correct answer to their question, and gives them and future visitors a terrible experience. This is why it's most important that askers decide the correct answer.

Questions that may not be the same, but are related

Another reason people suggest duplicates for not-exactly-the-same-question is because they feel the fact that they're related means they should be linked to provide as much useful information to visitors as possible. I don't disagree that relating other content helps build context and aids the site's consumers. However you have to realize by using dupe closure you're halting the progression of the question by disallowing answers to be posted. If someone has an exact answer to the exact question being asked, it would be incorrect for them to post it to the similar-but-not-the-same question which has been used as a dupe target, and it cannot be posted to the question which is now been closed as dupe.

If you want content to be related to build a larger picture for consumers of the context and concept at play, use comments to note the related content. Don't halt the questions ability to garner specific and correct content for the site just because it's similar to but not the same as another question which you feel is valuable.

I'm happy to hear criticism of my positions here, but overall as I said at the beginning, my perspective is based on the idea of future users experience utilizing our content catalog. I believe dupe closure can improve their experience, but the majority of ways it's used causes the exact opposite effect.


Looking at the big picture, I think there are two ways to address your concerns:

  1. If a question should be closed for a reason other than duplicate, close it for that reason. Only close as a duplicate if it is a good-quality question that would not otherwise be closed.

  2. Clean up the rat's nest of old, poor-quality, and off-topic duplicate targets. This may require deleting bad questions that point to them first.

You brought up a few examples in your comments. Maybe start another meta-question with some specific examples of old questions to nuke from orbit. It could be a third cleanup attempt. Keep it narrowly-focused on the worst offenders so we can make measurable progress and resolve it quickly, which is important for some of these old questions with a lot of dupe targets and upvotes which in turn requires a lot of delete votes.

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    I still haven't gotten around to attempting to read the question or the comments under it, but this answer is exactly my opinion on dupe voting in general, so +1.
    – Ixrec
    Commented Dec 13, 2015 at 16:57

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