What is the rationale behind only downvoting incorrect answers instead of voting to delete?

Question

It has been mentioned several times on MSO about downvoting incorrect answers but what is the reason for suggesting people only downvote instead of voting to delete, thereby leaving incorrect answers as still present on the site?

It costs reputation to downvote an answer, so it feels wrong to me that people are punished for pointing out obviously incorrect answers in the hope that they'll be rectified (so they can then remove the downvote if they notice it's been improved) or deleted (so the downvote is then nulled).

Why to we suggest people shouldn't vote to delete bad answers and to only cast such votes for non-answers / spam etc? Do we want StackExchange to be a repository for both correct and incorrect answers?

Yes, I know that the good answers will surface to the top and the bad ones will sink to the bottom, but that only assumes people are willing to sacrifice reputation to downvote - it is possible that such answers will get mixed in with the genuine low-vote answers that aren't actually wrong, just not very good.

Also, speaking as a moderator, why should I not delete obviously wrong answers that have been flagged as such by the community?

Answer 1

An incorrect answer sometimes illustrates a common misconception or anti-pattern. In these cases, it's useful to have the incorrect answer there (with all its downvotes) to show that the community thinks the answer is a bad one, so that when someone visits the page suffering from the same misconception they can see that their idea is wrong.

For example, here's a question that received several plausible but wrong answers, and it's a shame that they've mostly been deleted.

So downvote the wrong answer and leave a comment explaining what's wrong with it, but don't delete it.

Answer 2

1. Just because an answer has a score of -1 or less doesn't always mean it's wrong (or at least not entirely wrong). Sometimes an answer is misunderstood. Sometimes it has spelling/grammar/wording/formatting errors that can be fixed. Sometimes it is mostly correct but has one or two little mistakes that need to be fixed. All of these are issues that can be fixed either through good comments and/or edits to change the answer into something worth upvoting. If it's deleted, doing so is not possible.

2. Sometimes the users judging the answer are just wrong. Perhaps the answer is controversial, innovative, or not interpreted properly by the readers and downvoted despite it's correctness. While this isn't a common occurrence, deleting such an answer has a very high "cost" to the value of the site.

3. Leaving an answer that is just wrong on the site with a lot of downvotes, but not deleted, does not have a high "cost". It's clear to anyone coming to the site to look for an answer that the community feels that this answer is wrong, harmful, of low quality, or for some other reason shouldn't be acted on. Even for users not familiar with the site, the UI is very good at conveying that information to people. Combined with (one would hope) comments to further explain what the problem(s) are, readers can recognize that they shouldn't use that answer unless they know something the other readers don't, and even then such an answer should be used with much caution. (An example of this is that sometimes an answer is downvoted because the answerer misunderstood the question. The answer isn't wrong, it just doesn't answer the proper question. If a reader doesn't have the same question as the OP, but instead the question this answer answers, it can be useful for them.)

4. As others have said here, there is value to be had in keep around answers, even when they're just wrong. It shows you what not to do, and such answers also frequently have a lot of value in their comments in which users often explain why the answer is wrong and shouldn't be used.

5. Sometimes an answer has one or more mistakes or aspects of it that are wrong, but it still contains some information that's correct and valuable. Perhaps the approach isn't flawed, just the specific implementation and another person may come along, get an idea from that approach, and come up with a good implementation of it. Or, perhaps there is code that is fine but a poor explanation, or a good explanation but a poor example code snippet. The point is that some of the answer can be worthwhile (at least enough to not delete it), even if the entirety of it isn't.

Answer 3

Trusted users (20K+ on graduate sites, 4K+ on betas) can vote to delete negatively scored answers, and they should, when they honestly feel that the answer is harmful.

Every other user needs to flag for moderation attention to get an answer deleted, and moderators are not arbiters of correctness, that's not our role. We can downvote, comment or edit, as every other user, but not unilaterally decide whether an honest attempt at answering the question is correct or not.

Incorrect answers should be downvoted, that's exactly what downvotes are for. Even if you're a trusted user and you've decided to vote to delete an answer, you should also downvote it, you can't really assume people will agree with you that the answer should be removed.

Furthermore, the rep cost is minimal. Calling it "punishment" is an extreme exaggeration that sends the wrong message, most people avoid downvoting even the most obvious crap, no need to further encourage that. A far better description I've read recently for that 1 rep cost is that it's an investment in the site's quality, you give a little rep and get a better site in return.

Answer 4

You can learn a lot by reading an incorrect answer that has a comment or two explaining why it's incorrect. If it's bad enough to be embarrassing, can't the OP delete the answer?

Answer 5

Maybe because thhe answer still has some valid information? And even if it wouldn't, simply removing it removes all trace, while leaving it there with a comment can actually make a bad answer educational for both the person asking the question & the person providing the bad answer.