Notify visitors that the question is old

Question

I asked this question on meta.SE, it got marked as dupe for this question, I'm posting it here because it has more value here.

This question is 4 years old, someone commented:

Looks like the old accept is no longer valid... this is the reason accepts should float after a certain point in time... – Aaron Hall

I don't think that floating accepted answers, is the solution, because 4 years ago the answer was perfect.

My suggestion is that all questions are older than 2 years should have a banner like the banner of the duplicate question that says:

This question is old, the answers given may no longer work, you could sort them by date and try the newest of them and if none worked please flag the question to be archived.

If a question is flagged as old, it would still exist because it is still useful, but newer questions cannot be flagged as duplicates of the old question. And old question cannot resurface.

My proposal might be a good proposal for all stack exchange sites, but I think it's more useful for sites like Ask Ubuntu, my question is tagged 13.10, I think it's fair to keep it that way and just archive it.

If I unaccepted the accepted answer, I have no way of verifying which is the best answer and future users will look for votes, it means they would still try the old answer.

An automated solution based on the date and tags used is the way to go, on sites which suffer from having too many old questions.

Regarding the question: Automatic visual indication of old questions:

There are two answers. I disagree with the accepted answer saying users don't read.

I agree with the second answer saying that there's no way of determining if an old answer still works.

But I believe that such a visual indication is needed on Ask Ubuntu and others, because there's a high chance that the answer no longer works, in fact Ask Ubuntu refuses to answer EOL questions for that reason

Answer 1

I do think we need to think about and work on keeping the site up to date, but I am not convinced that we should push all old questions towards being "archived". Particularly if they have a lot of views, visitors will continue to land on them from search engines and from inside the site. I strongly believe old questions deserve as much attention as new ones, and giving them second class status will make it harder to maintain the overall site quality.

I believe questions that really are still useful should be maintained and improved by the community. For example:

• If current answers to a question are out of date, consider
  • posting an up-to-date answer
  • editing highly upvoted answers to maintain their usefulness if possible, avoiding throwing away legacy material entirely
  • adding a bounty to encourage an up-to-date answer
  • closing the old question as a duplicate of a newer one to lead visitors to up-to-date information. Flagging for merging may sometimes be a good option to bring answers about a topic together, but if old answers are going to end up on top (due to higher scores), not so much.
  • asking a new question (if you are a new user who can't afford a bounty, your problem is a bit different, seems version-specific, etc), linking to the old one to help contextualise, and to help visitors who land on the old question find the new one.
• Post a comment encouraging OP to change their accept if the accepted answer is obsolete (or otherwise bad), if they are still active.
• Rather than seeking to have a new question for the same issue in every version of Ubuntu, try to generalise questions over time. If an issue is common to many versions or near enough version-agnostic, remove version tags and confine version information to the question body or remove completely if possible.
• When an issue is version-specific, check whether it remains through a range of versions. Add version information to answers if needed.

Questions that are really not useful at all should be deleted, so visitors don't waste their time landing on them. Don't be afraid to use your down and close and delete votes to help rid the site of useless things :)