I'd frame the functional issue as follows:
Most questions can be categorically divided into three levels of "answered":
- Timeless: Questions with a timeless best answer, which is unlikely to be improved or updated in the future;
- Revolving: Questions with a "best answer" today but in the future there will be a "better answer"; and
- Wiki: Questions that are constantly being improved and updated.
Here are some examples of each:
Timeless best answers
Revolving best answers
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answers to so-called revolving questions the best answer may not be found on Stack Overflow — the information may be outdated.
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.
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:
- Reducing the number of near-identical questions occurring over time with different answers;
- Reducing the chances of less-than-ideal answers are returned in search results;
- Enhancing the functionality of "this is a duplicate of another question" by centralizing the discussion regardless of when the question was asked;
- Decreasing the number of "dead answers" that are no longer applicable;
- Revitalizing questions related to systems that have been changed since the question was first answered.