A moderator on one of the Stack Exchange sites provided the following answer regarding how one should determine whether or not a question is an "exact duplicate" or not:

Forget the "exact" wording. Whether a question is a duplicate of another can be answered by reviewing what information would be required to generally cover each question. If a good answer (even if such an answer doesn't exist yet) to one of the questions would cover the basics of the other question they can be closed as duplicates.

This seems to me to be out of step with what is explained in What is an exact duplicate?.

Exact Duplicate means that the question asked is the same question as one that has been asked before (the answers are irrelevant). In most cases, this means that the new question will be about a 95% match to the original.

The words "Exact Duplicate" are used because people find many reasons to vote to close questions as duplicates that are not really duplicates, such as:

  • Questions that cover similar ground, but are not really asking the same question.
  • Questions that have answers that answer the supposed duplicate, but the question is different.
  • Questions that duplicate a question asked on another SE site.

Am I missing something or is the moderator being too loose in the guidelines he is suggesting for closing questions as duplicates?

  • 1
    Your link is 5 years old, the notice once a question is closed as duplicate of another is "This question already has an answer here:" There's no more "exact" anywhere in the close as duplicate process.
    – Tensibai
    Apr 13, 2017 at 13:51
  • There is still the concept of an exact dupe, but that's almost always going to be a repost by another user or bizarrely enough, a repost by another user (sometimes coming years after the original).
    – user1228
    Apr 13, 2017 at 16:26
  • @Tensibai - as if to highlight the point, none of the answers in the "duplicate" had been accepted, whereas the one that I quoted was - which was why I chose it. I'm so confused.
    – guero64
    Apr 13, 2017 at 16:55
  • @Won't - according to this site moderators, they only have the "exact duplicate" message available when they close something as a duplicate. So is this a possible configuration issue with this particular site?
    – guero64
    Apr 13, 2017 at 16:56

4 Answers 4


The wording for duplicates was specifically changed to remove the word "exact" from the close reason precisely because the questions don't need to be "exactly" the same question. So long as the duplicate question provides a quality answer to the other question, it's a duplicate. The wording was specifically changed to define a duplicate question as one where the duplicate question answers the closed question (well).

If there are two questions that have differences that aren't relevant to the answers to the question then there's no reason to duplicate the answers. If what differences there are in the quesitons result in the answers to the existing question not answering the other question, or not answering it well, then that is when it is worth answering the other question.

  • On this particular site, the wording still says "exact duplicate"
    – guero64
    Apr 13, 2017 at 14:09
  • @guero64 It only says, "exact duplicate" when the duplicate question was asked by the same user, to specifically cover the case where they re-post the same question. If the authors are different then the close reason does not use the term "exact duplicate".
    – Servy
    Apr 13, 2017 at 14:12
  • @Servy it says "exact duplicate" for dupes with no answers regardless of who asked (e.g. How to review through the app ...but that is specific to meta)
    – Cai
    Apr 13, 2017 at 14:31
  • @Servy - on this particular site I am saying that the message does, in fact, say "exact duplicate" even though it doesn't meet the criteria you state. As long as enough people vote it to be closed as a duplicate, it gets closed as a duplicate and the "exact duplicate" message appears. There is no other message that appears when a duplicate is closed. That is why I am asking if perhaps this particular site is not configured properly?
    – guero64
    Apr 15, 2017 at 19:17

The moderators explanation is generally in step with how duplicates are handled, although I'd still take issue with the statement...

...would cover the basics

That's not really very helpful to someone asking a question.

If there are distinct differences which can't be covered in the supposed duplicate then it shouldn't be closed, but you (or whoever asked the question) needs to make that very clear, citing the existing question and explaining why exactly that doesn't answer the question.

If the suggested duplicate does answer the question then it more than likely should be closed, regardless of how differently it is worded or what different circumstances the problem came from (that probably gets a bit more complicated depending on the site, circumstances etc. but as long as the differences don't affect the answer then it shouldn't really matter).


As a moderator, and a long time user - duplicates are rarely exact. We often need to look at scope (On SU different versions and platforms for example) and "uniqueness".

I guess the big questions I ask are "Is this the same question?" and "Is this a subset of another question?". Very often, but not always, questions with the same answer are the same.

If so, I'd ask myself "Are there substantial differences between the questions?" An effective way of articulating that is to link a similar question and mention how it's different.

If all these criteria are met, it's a dupe. If it isn't - chances are no. Without seeing the actual question... who knows?

  • I think the question what should decide in these cases: "Does the OP (of the dupe candidate) gets his answer from the answers to the original question, on his apparent level of knowledge?" If the answer is yes, they are dupes. If no, they aren't.
    – peterh
    Apr 16, 2017 at 0:01
  • But that means a question asking to explain like I'm 5 is distinct from a general question which is distinct from an expert level question. A good answer tends to cover most of that IMO. Apparent skill levels are a pretty weak criteria to judge.
    – Journeyman Geek Mod
    Apr 16, 2017 at 0:06
  • Usually ok as long as it's in the spirit of my answers. That said these edits feel Minor
    – Journeyman Geek Mod
    May 18, 2017 at 8:43
  • 1
    Yeah. Just don't flood the front page and I'm fine. With new questions go ahead
    – Journeyman Geek Mod
    May 18, 2017 at 9:05

An exact duplicate means, that

  • at least 5, not suspended 3k+ users,
  • or suspended (or not suspended) moderator,
  • or a not suspended golden tag badge owner

signs that it is an exact duplicate.

It doesn't mean that they should be even similar. Thus, the "exact" word is in my opinion a false definition.

Particularly on the SO happens quite often, that people try to reduce the typically around 10000 question long close queue by a close-close-close rampage. We can consider it as pathetic actions to clean up the site.

I think, currently the continuous assault of the LQ content is more harmful for the site, as the - unfortunately, still too many - falsely closed questions.

The problem could be solved if the golden tag badge owners would get a priority in the review queue to handle the questions in their competence first. Although it may give them too many power what they wouldn't surely use for good. Unfortunately, the SE doesn't seem to have the required computing power to implement it.

  • "It doesn't mean that they should be even similar" is complete fiction; in the very worst cases the questions are at the very least "similar"...
    – Cai
    Apr 15, 2017 at 17:15
  • "The problem could be solved if the golden tag badge owners would get a priority in the review queue to handle the questions in their competence first" You can filter reviews by tag already but I don't see how that affects the issue here at all...
    – Cai
    Apr 15, 2017 at 17:15
  • 2
    ...and why the talk of suspended moderators? Has that ever happened?
    – Cai
    Apr 15, 2017 at 17:16
  • @Cai I've faced many times falsely closed dupes. "Exact duplicate" should mean a byte-level dupe or at least a very low Levenshtein-distance, it doesn't happen. I think the definition would look better without the "exact" string.
    – peterh
    Apr 15, 2017 at 17:17
  • @Cai Yes, it can, but not too long (Shog would demod both of them on the first spot). Somewhere I've read, two mods once tried this as an experiment. But, in theory, a suspended moderator can still do anything, including the closure of questions as dupe, thus the diamond is stronger as the cage.
    – peterh
    Apr 15, 2017 at 17:19
  • @Cai The broader context of the problem is the continuous assault of the LQ content against the SO, and as a side-effect, the many falsely closed content, too.
    – peterh
    Apr 15, 2017 at 17:21
  • Sure, there's nothing wrong with thinking the definition should be changed from "exact" and I'm not arguing with your point about "falsely closed questions" (I'm not agreeing either)... but that doesn't make the rest of what you said any more true.
    – Cai
    Apr 15, 2017 at 17:23
  • and a moderator possibly being suspended as an experiment once upon a time doesn't exactly make it worthy of including in a list of people who can close a question...
    – Cai
    Apr 15, 2017 at 17:23

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