How to deal with old question and old information?

Question

I find lots of questions about "How to arrive from A to B?". The problem is that as they get old they get outdated. There might be cancelled transports or new ones. This might seem relatively trivial but as CGCampbell mentioned in his comment this might actually be very serious. The example given with the VPN's in China is very illustrative.

How to deal with this if I need updated information? If I ask the question again, I will sure get complaints saying it's a duplicate. I can make a comment and ask the person who answered to update, but that's a bit limited in scope considering we have whole comunity that might have better answers, not to mention the person might not have new information.

There are at least 2 situations:

• You know the information is outdated, but you don't have (enough) knowledge to update it.
• You have no idea if the information is outdated, but by the age and by the nature of the question you know you cant blindly trust the answers

What would be the most adequate procedure to get refreshed information?

Answer 1

I have some thoughts on this:

• Adding a new answer if you know the answer;
• Or, leaving a comment that the answer is obsolete. So, in the future the question finds its way to surface again, everyone will know that it's obsolete and someone might know the answer and provide a valid answer or edit the old answer.
• Adding a new "post notice", where community can flag an answer as obsolete and then it will marked as "obsolete" until it's edited or flag is removed by a mod.

For those who do not know what a post notice is, check this question, you will see a notice:

Post is related to a rapidly changing event.

Answer 2

When I've been in the situation on other SE sites of finding obsolete information and needing up to date information, where I've not been able to add the new up to date answer myself because I don't know what it is yet, what I've tended to do is ask a new question roughly like this:

How to do X in 2015

I've read How to do X, dated 2009, but the answers no longer apply - XX is now YY, and ZZ can no longer PQ because it's on fire.

How can I X with things as they stand as of October 2015? For example, without encountering problems due to ZZ being on fire?

From my research I've found that a burning ZZ can still resist tornadoes on Thursdays, but that's no use for me because I'm not a vegetarian.

Key features:

• Time period in title. This is also good SEO because when the internet is full of outdated info on a topic, people will tend to include the year (e.g. it'll stand out for people using searches like Border crossing Kyrgyzstan China 2015)
• Address the non-dupe head on in the first paragraph, being as specific as possible about what you know has changed. Many trigger-happy vote-to-close addicts will still cheerfully ignore this, but hopefully they'll be outnumbered by conscientious users
• Link to the non-dupe so that someone googling "How to do X" then landing on the out-of-date info can see "How to do X in 2015" in the related content box
• Then all the usual good question stuff like showing your research and giving relevant context

Answer 3

Definitely leave a comment pointing out that the answer is outdated. It'll inform others about the problem. However, if you know that the answer is outdated you also know the updated answer, or at least part of it. So you should add an answer.

The other option you have is to offer a bounty asking for an up-to-date answer.

Answer 4

We always seek for canonical answers as much as possible here as far as my understanding goes.

The problem is that, at least TSE, some answers might change over time even if canonical at a given time. The solution for a given problem might be transient. There should be some sort of flag to indicate this clearly to readers maybe.

If a reader hits such an answer he should be clearly informed that the answer holds true at a given time point, and maybe allow the reader to ping whoever to bring attention to this answer again.

What kind of answers should have this:

• transportation, specially late night or remote areas (are there transports to X at 12PM;)
• questions which the content is inserted in politically unstable areas (eg: is it safe to visit ... ?; Can I do... in ....?)
• other? please contribute.

I know that defining what late is or what politically unstable is can be relative, but security should be prime here. The user should be alerted o the fact the answer might change and to double check if it still holds true before blindly take the information and try to use it.