When should I delete an answer? has an early exploration of a rationale for when answers should be deleted by 20k voting. Unfortunately, time marches on and the reasons explored in the sole answer basically map perfectly to NAA or VLQ flagging reasons, or at least Recommend Deletion in LQP. (They're also mentioned in the Help Center anyway now.)

But I'm pretty sure 20k answer deletion is supposed to be a little more than just "you can now directly vote to delete what you used to have to review-vote, and sometimes that means it gets deleted faster". What are some examples?

  • Late bad semi-dupe answers? (These are hard to reliably push through with VLQ-flagging, but not impossible, and ♦ flagging usually works.)
  • Trolling/non-serious answers? (For example, a ridiculous definition of a word on ELL that might embarrass someone if they took it seriously.) In some ways, these might be considered similar to the various PHP security anti-pattern answers we've dealt with on SO, since most of those with any claim to expertise in the subject would recognize them as bogus, but anyone credulous enough to rely on them will find them actively harmful (if they ever find out at all). The difference is that the wrongness is generally a lot more obvious to ordinary semi-experts, not just the rockstar security consultants, so there's no question of deleting/modifying a highly-scored answer. Of course… that arguably makes them nearly toothless. Hmm.
  • Answer that blatantly ignores one or more constraints in the question, like a Java answer on a C# question, a D&D answer on an Exalted question, or the like? (There are usually arguments made that these don't fit NAA by the letter of the law, and VLQ is not terribly obvious either, but LQP reviewers usually do the right thing anyway.) Much like joke answers, these usually don't require more than a small amount of expertise in the subject.

I can't think of anything else, and I'm not convinced the first one is actually worthwhile. So what I suspect is that while there are a number of situations that delvoting works well in, they are sufficiently unusual it's hard to find centralized references to them. I'd like to know which ones those are, so I can run more effective routine searches (on the site I have the priv, I check 10k tools once a day, normally) or just keep an eye out.

  • If an answer is a perfectly well written answer to a completely different question... Nov 24, 2015 at 6:28
  • @RobertLongson: I guess, although that seems like something a comment plus flag can often solve via queue. Nov 24, 2015 at 6:57
  • a comment still leaves the answer as noise on the question, what are you going to flag it as? Moderators aren't subject matter experts and won't therefore delete it. Nov 24, 2015 at 6:59
  • @RobertLongson: VLQ, generally, which usually does the job. But I suppose that's worth considering anyway. Nov 24, 2015 at 7:07
  • This likely varies site by site. Some seem to be much more "noisy and low quality answers that harm the S/N ratio" and others are "nothing should ever get deleted if it addresses the question". And while SE may have some guidance on the subject, there is a significant bit of "the community on the site will do what it does."
    – user213963
    Nov 26, 2015 at 3:26
  • @MichaelT: Hmm. I suppose I may need to try the site meta then, although since I'm one of the most active members there, that ... may not be terribly enlightening. Nov 26, 2015 at 3:28
  • 2
    While I am uncertain of the authority with which this is stated (it appears to be from a former community manager from half a decade ago), I believe this is a very good answer to your point. Should a joking answer be deleted (or was it not aparent this was a joke)?: "Joke answers have extreme negative value here. They destroy our signal/noise ratio, which is one of the most important advantages of the SE format." It goes on with many other good points.
    – user213963
    Dec 7, 2015 at 0:13

1 Answer 1


The general SE guidance is covered in Why and how are some answers deleted?

Answers that do not fundamentally answer the question may be removed. This includes answers that are:

  • commentary on the question or other answers
  • asking another, different question
  • “thanks!” or “me too!” responses
  • exact duplicates of other answers
  • barely more than a link to an external site
  • not even a partial answer to the actual question

And in Privileges > Trusted User

You may vote to delete answers in the following cases:

  • The answer is extremely low quality: There is little to no scope for improvement
  • The answer doesn't attempt to answer the question; it may be a comment or a separate question altogether.

Another view from Jeff back in '11 that had an emphasis on popular questions: How aggressively should we maintain and improve very popular questions? had as its last point for outright deleting (not combining):

If answers are to be outright deleted and not combined, they should be provably bad by concrete metrics.

We know that quality equates strongly with length (TWSS). Therefore, answers that are strong candidates for deletion:

  • belong to low rep or anon users with no real commitment to the community
  • are provably duplicate, that is, were added well after (30+ mins later) other answers that contained the same exact information
  • are short in length
  • do not explain much of anything

On many sites, moderators have taken the stance that they will not evaluate the contents of a post when deleting an answer — that if the answer seems to mention the same words as the question, it is an attempt at answering.

However, that's something about flagging and if you have a reasonable expectation of the moderators acting on a "not an answer" or "very low quality" or "this answer is something that should be deleted because..." custom flag.

As a trusted user, however, this is something of curation rather than moderation. That balance is something that each community tends to settle on.

Some communities work for a very high signal to noise ratio and will delete answers that do not contribute to the signal. From some stats a while back (granted, this is for questions — not answers) you can see that some sites are more active than others in deleting questions (it would be interesting to see the stats for answers).

Other communities are very hesitant to delete answers.

Doing a rough "what's out there" look with a query of is:answer score:..-1 you find things like:

  • Skeptics having only 446 down voted answers on the site (out of 7,725).
  • Math having 7,858 (out of 760,345)
  • Programmers having 3,554 (out of 126,601)

However, this only gives us half a hint at the answer delete voting culture on the site.

Tossing together a quick query (data.se) gives us a better hint about the posts currently undeleted on the site:

site           delete     neg   total   del/neg  neg/total
Math             1465    7813   756468  18.75%    1.04%
Code Review        56     326    49733  17.17%    0.65%
English          1273    7911   158652  16.09%    4.98%
Gaming            570    5172   102784  11.02%    5.03%
Programmers       268    3445   126504   7.77%    2.72%
EnglishLL          78    1148    36889   6.79%    3.11%
MathOverflow       48     780   105753   6.15%    0.73%
StackOverflow   11799  281664 17323405   4.18%    1.62%
ServerFault       237    6279   366173   3.77%    1.71%
SuperUser         360    9621   444827   3.74%    2.16%
Skeptics            3     443     7706   0.06%    5.74%
Bicycles            2     380    19194   0.05%    1.97%

As mentioned above, this is not deleted answers. The reason that this is slightly more useful is because once you go down the 'deleted answers' route you start having to decide if you want to filter out the answers on deleted questions, or answers deleted by mods, or answers converted to comments by mods, or answers that are negatively scoring that were deleted when the user was deleted, and so on. The undeleted answers with delete votes on them probably gives the best view into the current trusted user voting patterns... and things where very few may indicate a more active trusted user delete voting that is cohesive in their deleting (a more black and white situation).

The thing I'm endeavoring to show above is that there are a wide range of SE sites and the way they down- and delete-vote answers.


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