I feel like this answer should be downvoted because it is at the top of the page and outdated. However I'm not sure whether or not that is the best idea. Is there a better solution to this problem? Or it might not be a problem?
Here's my two cents on this. I'm going to talk in very general terms, because the question applies not just to one you linked, but to many other out there. And remember, this is just my personal opinion on this.
Voting is the measure of usefulness of an answer, not of whether an answer is outdated. If you ask a current question and receive outdated answer, then logically it is not useful - down-voting that is OK.
Downvoting an outdated answer on outdated question, however, is not logical and achieves no useful purpose (especially if downvoted without comment). At the time of writing it may have been both useful and relevant. Best course of actions in my opinion (disclamer, this is just an opinion) would be:
- leave a comment requesting the author to update the answer; especially in case of high-reputation users, there's a high probability they're active on the site and will see your comment
- if the user haven't answered and you don't have editing privileges - bring it up to the attention of users in Ask Ubuntu General Chatroom or Downboat Chatroom. Alternatively, request it here on meta site, especially if you are not sure how to proceed or how exactly information should be edited. After all, Ask Ubuntu is a community, so talk to people.
- if you do have the privilege to edit posts - do that, however do so in non-destructive way; that means, do not delete the original content of the answer. Remember, the answer in question was relevant in the past, so it may have (1) historic value, (2) it may be referenced by other more recent posts discussing what has been going in the past, (3) believe it or not, there are people out there who still use legacy Ubuntu releases or legacy software, and the solution may actually be useful to them.
- Another option is to post your own answer to cover the new material, with perhaps commenting on the outdated answer. This doesn't improve the other answer, obviously, but does allow for upholding relevance of the question; don't worry whether your answer won't be as highly voted - Ask Ubuntu is not a marathon, but more like a wiki; those who read whole posts and actually look for up-to-date stuff will find it.
NOTE: Please do not flag posts for moderator attention; this is not their job to keep answers up to date (unless the answer could be potentially harmful, then it could be argued that it's under their jurisdiction). In other words, don't bother moderators with what community or high rep users can do alone.
Now, what about downvoting itself ? You certainly can do that, and you can get away with the excuse "I'm downvoting the answer because it is not useful anymore". That's all fair and square, voting is anonymous, and you don't have to even explain why you downvoted an answer.
However downvoting without explaining achieves no useful effect, and you really need to figure out what is your purpose - do you just want to silently disagree, or actively partake in making information relevant. You downvote an outdated answer, OP might see it and just ignore it; old answer, who cares. By contrast, if you downvote and leave a comment, if the author is on the site they will update the answer. But then again, downvoting isn't even necessary.
In other words, when it's about relevance/up-to-date-ness of an answer, voting alone isn't useful when done by itself. That's why best course of action is editing and communicating with author of the post.
No, that's very rude in my opinion. I think there are better alternatives.
The answer needs additional details
If the original answer is correct as it is at the time of posting, but now requires additional info to cope with newer systems/updates, you can do one of the followings:
- Edit the answer yourself and add the details.
- Leave a comment with the details and suggest the answerer to append the details to the answer.
The answer is completely obsolete (but was correct at the time of posting)
Just leave a comment saying it's out-of-date or just leave it as is. I believe users will see the date of posting/last edit and figure out that the answer might not work with a newer system.
If you have a up-to-date answer feel free to post it. If you think you have a (Ask Ubuntu) link to an up-to-date answer, edit the outdated answer and append the link.
Another way of doing is to tag the answer with the Ubuntu version when possible. That is, add a sentence to the top of the answer:
## Ubuntu xx.xx and older. But this would require to update other answers as well and specify which one is for versions newer than xx.xx. This helps users skip the outdated answers altogether, and look for the appropriate one. For example: Apache error "Could not reliably determine the server's fully qualified domain name"
The question itself is obsolete
You can vote/flag the question for closure. There is an option under Off-Topic which goes like this:
This describes a problem that can't be reproduced that seemingly went away on its own or was only relevant to a very specific period of time. It's off-topic as it's unlikely to help future readers.
Of course if the answer is completely wrong/rubbish/potentially dangerous to begin with, downvoting (maybe also leave a comment pointing out the problem(s) with it) is the right action to take.
If the answer is no longer correct and you can fix it, then edit as pomsky suggested. If, however, it is now completely obsolete, so much as to be irrelevant, then yes you should downvote.
Sadly, a lot of people take downvotes personally, which is silly. The whole point of the voting system is to put the right answer at the top and put wrong answers down. So if an answer which is currently wrong is at the top, it needs to be downvoted. This isn't "rude" and it isn't "mean", it is helping the site and improving the site's content.
Yes, voting also acts as a reward system and turns the site into the game we all enjoy. However, we should not forget that the point here is not to amass Useless Internet Points®, it is to create a useful repository of knowledge that will help people solve their technical issues with Ubuntu.
Voting is an integral part of that and downvoting is fully as important (if not more so) as upvoting. So if an answer is now wrong, even if it were perfect when posted, it should either be fixed or downvoted to show that it is no longer correct.
Now, practically, it is almost always possible to edit and fix an answer or, at least, to add a diclaimer explaining that this is no longer relevant and/or is limited to specific versions of Ubuntu. So usually, you don't need to downvote and can just add the disclaimer. However, in cases where that isn't feasible or where the answer which used to be fine is now dangerous a downvote is the right thing to do. You always vote for the current situation, not the past.