Expiration of answers for questions with novel solutions

Question

A lot of questions seem to be answered at the time an answer is posted, but a year or two down the road there are clearly better answers.

Is there any mechanism for flagging a question as one that needs 'revisiting', or alternatively marking answers as 'expired' -- as an alternative to posting new questions along the lines of "I've seen answer X to question Y, but X is outdated and I was wondering if there were newer and better solutions?"

Some question clearly have a 'best answer' that's regularly updated essentially as a wiki. Other questions are clearly have one-time final answers. However a large segment clearly follow the model of 'this is the best answer today, but check back later', particularly for questions about actively developed systems (e.g. best answers for python 2.X may not be the best, or even possible in python 3.x).

One potential consequence of this 'revisiting' / 'expiration' mechanism is a flood of redundant questions that have already been answered.

I'm just curious as to what others think of this, and whether perhaps it's been thought of before -- though I couldn't seem to find anything.

Answer 1

Framing

I'd frame the functional issue as follows:

Most questions can be categorically divided into three levels of "answered":

1. Timeless: Questions with a timeless best answer, which is unlikely to be improved or updated in the future;
2. Revolving: Questions with a "best answer" today but in the future there will be a "better answer"; and
3. Wiki: Questions that are constantly being improved and updated.

Here are some examples of each:

Timeless best answers

• MacVim and Mercurial check-in — The solution is and always likely will be the one given.
• How does one insert a backslash or a tilde into LaTeX? — Because LaTeX is largely unchanging, the best answer is unlikely to change.

Revolving best answers

• Python reverse / inverse a mapping — The best answer for Python 2.X is a dict(), but in Py3 it's a map comprehension.
• How can I parse JSON in Google App Engine? — the answer is currently django.utils.simplejson, but if & when GAE is updated to Py3, a better answer is the builtin JSON library.
• jQuery UI dialog positioning — The selected answer is using a plugin such as 'cluetip', but a better answer (I believe) since jQueryUI 1.8 came out is the jQueryUI position utility.

Wiki

• List of freely available programming books — The compilation will change as more books are created.
• Hidden features of Python — There are many answers, with continuing contributions, but no real 'best answer'.

The functional issue is that when people search for answers to so-called revolving questions the best answer may not be found on Stack Overflow — the information may be outdated.

Proposed solution

Here is a suggestion for a solution:

When a question reaches a certain age, eg a year of age, allow users of sufficient reputation to flag a question for a "revolution". Once a sufficient number of revolution flags have been placed on the question (e.g. five), the question is "revolved".

A question is "revolved" by removing all answers to the question. When a user looks at a "revolved" question though it will say a remark such as:

This answers to this question have been revolved on the basis that users X, Y, Z believe that changes in circumstances have lead to the possibility of better answers. You may wish to view the answers from previous revolutions [link] before answering this question.

History of revolutions

At the same time as a question is "revolved", there should be a "History of revolutions" link and corresponding set of pages that show prior answer sets.

Votes and reputation

As the answer to a "revolved" question may be built upon previous answers, and to prevent abuse by those who regularly revolve a question, it may be worth considering reducing the value of votes on revolved questions e.g. by half the value of votes on first-instance questions.

Alternatively, and pointedly to reduce abuse, those who flag a question for revolution could be denied reputation for any answers they provide to that question.

Conclusion

While not a critical feature, this issue will become more germane as Stack Overflow – and its repository of answers – matures, and the suggested solution is meant to serve the following purposes:

1. Reducing the number of near-identical questions occurring over time with different answers;
2. Reducing the chances of less-than-ideal answers are returned in search results;
3. Enhancing the functionality of "this is a duplicate of another question" by centralizing the discussion regardless of when the question was asked;
4. Decreasing the number of "dead answers" that are no longer applicable;
5. Revitalizing questions related to systems that have been changed since the question was first answered.

Answer 2

It's worth pointing out that all of the revolving examples actually are timeless answers if the questions are thorough and specific. The problem isn't that questions are revolving. The problem is that the questions are not as specific as they could be.

For instance, if this question were asked with a specific version in mind, then it would be classified in your "timeless" category:

Python reverse / inverse a mapping — The best answer for Python 2.X is a dict(), but in Py3 it's a map comprehension.

If the question were: "What is the best way to invert a map using Python 2.X?", then the answer "use dict()" would be a timeless answer, as the Python developers are not likely to retroactively update or release a new version of Python 2.X anytime soon.

What is the best way to parse JSON in Google App Engine Python SDK 1.2?

The answer to this question will always be the same: django.utils.simplejson.

What is the best way to parse JSON in Google App Engine Python 1.4.X?

However, the answer to a new question specifically targeting version 1.4.x, which we'll assume uses Py3, the answer to this question should again always be the same.

Now, the question we must answer is: Do we need to include this level of granularity and detail in questions to prevent them from becoming incorrect? Will it be better for the question to become obsolete because no one cares about an old version of App Engine, or is it better for the question to be incorrect?

Answer 3

Currently there's no mechanism for marking an answer obsolete, other than down-voting. However, you have to bear in mind that some people still have to work with older technologies for all sorts of reasons so what you think is outdated may well be just what someone else needs.

There's always scope for providing more up to date or potentially better answers, so if you can, do so.

This will bump the question to the top of the active tab (and probably the interesting tab too). If others agree they'll up-vote your answer. The OP may even see and switch the accepted answer if you're lucky.

As of September 2021 there's an experiment to see if unpinning the accepted answer makes any difference to how new answers are voted on and used. If this provides good data it may lead to a permanent unpinning which will allow newer, better answers to rise to the top of the page and be a lot more visible.