What is meta? ×
Meta Stack Exchange is where users like you discuss bugs, features, and support issues that affect the software powering all 149 Stack Exchange communities.

Bravo for allowing comment editing, but what's the explanation for enforcing a five-minute window?

I think this might be over-engineering. If I have a spelling mistake or an inaccuracy I'd like to fix, I don't think the fact that five minutes has elapsed should prevent me from fixing it.

Further, if you are worried people will edit their comments in a way that makes the comment thread nonsensical, they can already do this by deleting their comment. So, limiting the ability to edit isn't really helping much in that regard.


If people don't like this idea, I'm definitely open to hearing your reasons. For now, it seems like an unnecessary limitation of a quite awesome feature.

Update 2

Regarding John's scenario...

Me: Obama is cool!
You: You are right, man!

My edit: Obama is an idiot!
You: You are right, man!

...this problem can still occur with deletions...

user1: Obama is cool!
user2: No, McCain is cool!
you: @user2 is right, man!

user1: Obama is cool!
---- deleted -----
you: @user2 is right, man!

So, yes, editing could be abused as you suggest, but discontinuities can occur already because of deletions (and as someone else mentioned, because upvoted comments get prioritized upward).

As for Jeff's argument about rate limiting, I agree that is important, but I don't understand why you can't just use a CAPTCHA to prevent too many edits in a short period of time.

share|improve this question
Duplicate of meta.stackexchange.com/questions/33952/… –  John Rudy Dec 28 '09 at 20:14
I reworked my question to be a feature request, so it is no longer a duplicate (that I know of). –  devuxer Dec 28 '09 at 20:46
Changed the title to reflect this. I still think it's a lousy idea though. There's no revision history for comments, and that makes editing - especially very late editing - problematic. –  Shog9 Dec 28 '09 at 20:50
Shog, That is definitely a better title, thank you :) –  devuxer Dec 28 '09 at 20:51
Late deleting is no less problematic (and probably more), however, but that is still allowed. I think the fear that editing will cause users to destroy the continuity of comment threads is unjustified. –  devuxer Dec 28 '09 at 20:54
Now it's a feature request and I voted to reopen it. Also it is a bad idea therefore I downvoted it. Hope you are happy now :) –  Ladybug Killer Dec 28 '09 at 21:11
Given all the changes that were made to this question to ensure that it was not a duplicate, why was it still closed? I don't understand. Also, the Possible Duplicates listed at the top of the question are in fact not duplicates. –  devuxer Dec 28 '09 at 21:11
Thank you John...and if you think it's a bad idea, I'm open minded. Just tell me why you think so. –  devuxer Dec 28 '09 at 21:12
Reopening since it's no longer a duplicate –  Kyle Cronin Dec 28 '09 at 21:14
@DanThMan: Be patient! You need 5 reopen votes or a mod like Cronin to reopen a question. –  Ladybug Killer Dec 28 '09 at 21:16
@John, hey now, at least one person voted to close my post after it had been fixed. That's what I was objecting to. I understand the reopening process (and I'm glad it occurred). –  devuxer Dec 28 '09 at 21:23
Actually, when I first read the window was 5 minutes, I thought that was really long. –  GManNickG Dec 28 '09 at 21:29
I voted to close because I still think it's a duplicate of meta.stackexchange.com/questions/25831/…. That's where the five-minute window came from. –  mmyers Dec 28 '09 at 21:29
@DanThMan: Jeff deletes comments faster than you edit! –  Ladybug Killer Dec 28 '09 at 22:27
Heh, and a user changing their name doesn't break the comment thread? Who's this "John" you keep talking to ;) –  Zhaph - Ben Duguid Apr 8 '10 at 12:39

4 Answers 4

up vote 24 down vote

Reasons for eliminating the five-minute limit

  • Late changes are sometimes needed and not necessarily due to mistakes. For example, links might rot and have to get replaced by new ones.

  • Comments are supposed to claim a few space as possible. Editing an existing comment, rather than posting a new one, accomplishes that.

  • Right now, if I have to make an important change (e.g., botched link) after the grace period expired, I'm left with two choices:

    1. Post the intended edit as a new comment and delete the existing one.

      This completely breaks the context if somebody has replied already.

    2. Post a second, clarifying comment.

      Again, this clutters the comment section.

  • Typos make the site look ugly and are embarrassing for the poster.

Addressing possible abuse scenarios

  • Chameleon questions are already a problem. If the five-minute limit is removed, chameleon comments might become a problem too, especially since existing responses will lose their context.

    But deleting comments already leaves subsequent comments without a context. Also – as @PopularDemand already said – comments aren't supposed to contain [...] important information, so lost context isn't really something to worry about.

  • As @LadybugKiller pointed out, somebody might change their comment maliciously and put words into a user's mouth if he responded You are right, man!.

    But nobody is actually supposed to respond You are right, man!. That's what comment upvotes are for.

  • Comment upvotes may get misinterpreted after an edit.

    But this is easily fixed by removing all existing upvotes after an edit. Also, undoing comment upvotes is already possible, so this might not even be needed.

  • Comment edit might be used to cloak abuse.

    But this is easily fixed by disallowing edits (and deletion?) after a comment has been flagged as rude or offensive.

  • As @JeffAtwood said, [a]nything that isn't rate limited will inevitably be abused.

    But the current implementation isn't a rate limit; it makes late edits impossible. Limiting the possible comment edits per minute (no CAPTCHAs, please), seems like a better choice to me.

Also, all possible abuse scenarios (that I could think of) are already affected by the current implementation, since comments may get several responses within the grace period.

Revision history and timestamps

@Shog9, @0A0D, @JeffAtwood and @jadarnel27 all mentioned (the lack of) a revision history, which – if implemented – it would render all abuse concerns moot.

If that's too expensive to implement (I assume it would be much more expensive than just abolishing the time limit), maybe it would suffice to just change a comment's timestamp after each edit. That would at least take care of @LadybugKiller's scenario.

share|improve this answer
Get ready for some rep, baby! –  Won't Jun 20 '12 at 15:36
I think it might be necessary to have a comment revision history if this were in place (like the one for chat messages, for instance). –  jadarnel27 Jun 20 '12 at 15:42
"Late changes are sometimes needed and not necessarily due to mistakes." If the comment was important or worthwhile, the link should have been absorbed into a question or answer as appropriate. Comments are ephemeral; treat them as such. –  Nicol Bolas Jun 21 '12 at 2:06
@NicolBolas: Whenever possible, yes. But I can hardly incorporate a link into an answer if I'm trying to prove it wrong. –  Dennis Jun 21 '12 at 2:18
This is a very well-put set of arguments. I hope it is found convincing. –  Dewi Morgan Jun 21 '12 at 2:34
@Dennis: You can prove it wrong in your own answer, either by just obviously being right or by making a argument that the given alternative isn't right. Furthermore, if it is indeed wrong, the link won't have rotted before the answer has received its downvotes and been made irrelevant. –  Nicol Bolas Jun 21 '12 at 2:46
@NicolBolas: Wouldn't an answer, posted solely to point out the flaws of an existing answer, be either deleted or converted into a comment? –  Dennis Jun 21 '12 at 2:50

I am worried about people changing their comments to give a thread (the following comments) a complete new meaning. Making it nonsensical is one of the better things that could happen. Shog9 is right in his comment: there is no history for comments. That's the main problem.

Easy example:

Me: Obama is cool!
You: You are right, man!

My edit: Obama is an idiot!
You: You are right, man!

There are enough jerks out there, who think things like that are funny. They can really mess SO up with that.

share|improve this answer
Who is this Obama guy, anyway? –  balpha Dec 28 '09 at 21:28
+1 This should be the accepted answer.. though there is no perfect 'grace period'... 5 mins seems to be the universally accepted standard for comments, questions, and answers for the trilogy sites so any longer would upset the balance - though if there was a revision history then the 5 min rule would no longer apply! –  staticx Dec 28 '09 at 21:29
@balpha: He used to be on Meta, I think... –  mmyers Dec 28 '09 at 21:46
John, thanks for you answer. I added an update to my question in response. –  devuxer Dec 28 '09 at 22:04
@mmyers I heard he got elected to be a mod somewhere after he left. –  Asad Jun 24 '13 at 21:57
I challenge you to find a single location on the net - anywhere - where this has been done maliciously. It's done, occasionally, as a good-natured prank among friends, but I can find no evidence that this is a regularly-abused feature anywhere. –  Dewi Morgan Jul 30 at 19:48

Anything that isn't rate limited will inevitably be abused. This is a fundamental law of human behavior.

Remember that comments are lightweight and unversioned.

You might also consider why Digg comments and even Skype chat (where the pencil icon was cribbed from) have the same exact "editable for a small period after creation, then locked in forever" behavior.

share|improve this answer
Jeff, I've read that blog post (and it's good), but why is the solution a time limit rather than a CAPTCHA? –  devuxer Dec 28 '09 at 22:00
@Dan, that's where "lightweight" comes in; comments aren't supposed to contain the really important information anyways. And don't forget you can always delete a comment and write a new one if you really have to. –  Pops Aug 29 '10 at 17:26
rate limiting != time limiting. One is a useful anti-abuse tool, the other is an accessibility nightmare. [edit: enter posts comments? I didn't realize. And now I have only five minutes to finish this comment. I am so glad I am not disabled, and am mostly fluent in English.] –  Dewi Morgan Jun 21 '12 at 19:27
Then I think they probably need to get versioned. (Can't moderators already see a comment's history? If they can't, they should. That's important.) –  minitech Jun 21 '12 at 19:29
@mini constraints help people get things done. If you could live forever, why would you ever have any urgency to get things done, ever? –  Jeff Atwood Jun 21 '12 at 23:43

I always find it a little discriminatory that people with fully-working limbs, familiar and comfortable in their language, set their input requirements as if everyone else is in the same privileged position. [Edit2: note that this behavior is fine for defaults - just really bad for requirements.]

What happened to accessibility being important?

For someone who's second-language English, five minutes is barely enough time to check a couple of words, let alone compose full sentences and paragraphs. Why should only those who are fluent be permitted to edit?

Someone who's using text-to-speech or other disability input, who may even commit their comment early by accident, now must flail with their close-to-impossible-to-use hardware before the timeout. Timeouts are a slap in the face to disabled people using such devices!

That I can find, there is absolutely no evidence, anywhere, that the ability to edit comments is more abused if there is no time limit. I honestly cannot find a single scrap of evidence, a single maliciously-edited-after-five-minutes comment, anywhere on the net. Perhaps my Google-fu is weak today, but no: I think this is just that programmers are used to the mindset of adversarial thinking, at the expense of accessibility.

Yes, it might get abused. There is no perfect way to avoid this, and there are systems already in place to deal with that when it happens. Comments can get abused even without editing, and there's nothing new there.

If someone edits their comment, then at least if there is no timeout, people who notice that edit later can edit their own responses in return. So by adding a timeout, you are making it easier and more effective to abuse commenting editing, instead of harder and more pointless.

If editing is worth having - and clearly it is - then it is worth having properly, not a half-assed, unfriendly "well, you can use it to fix a couple of quick typos, but that's IT!" version.

As others have said, I have indeed encountered the timeout elsewhere, and I abhor it in every incarnation: you spend 10 minutes editing your comment with extra, helpful stuff; you click submit... and all your research is lost to an error message telling you that you were too slow. Why? There is no earthly reason, other than to annoy legitimate users.

[Edit: in testing, here, you at least don't lose the edits: they just become pointless, and have to go out of chronological sequence, and you get pointlessly annoyed and have to copy, paste, and repost, and are reminded once again about what appears to be just a poor design decision.]

share|improve this answer
+1 Good point about users who are learning languages. I hadn't thought about that, but it is true. Since it seems everything on Stack Overflow is in English, many people are having to learn a new language in addition to learning the site-specific markup, which has instructions given in English. –  ctype.h Nov 17 '12 at 3:26
+1 for "Yes, it might get abused. There is no perfect way to avoid this, and there are systems already in place to deal with that when it happens." That's been the rationale behind several other good decisions to change things that didn't work well, and it's a good argument here as well. –  Dan Henderson Jul 30 at 13:14

You must log in to answer this question.

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