Maybe this has been proposed before, but I couldn't find anything.
Many times it happens that a question is asked, some answers are added, and then the original poster changes the question in such a way that the answers are no longer relevant. This makes the answerers look like fools in some cases (and they often get downvoted)
Can anything be done to prevent this on SO?
A possible solution would be to only allow adding to an existing question when one or more answer has been added. Just a thought...
By "adding" to a question, I don't mean only allow comments, but prevent the original content from being edited by the OP. They can only add extra text below the original text. Others (with high enough reputation) can of course edit all the content if required.
This piece of text under the header "Clarification" is an example of what I mean (I added this after the first answer was posted here).