Say I have an answer which gets 30 upvotes. After a time I realize the answer is wrong. Should I:
a) delete the answer?
b) edit the answer to be correct?
My concern with the approach in b) is that whatever I write in my new answer will not be vetted by the 30 people who upvoted my original answer. Since they aren't notified of the changes, I don't think it is fair to keep their stamp of approval attached to whatever I write. That would amount to the 30 upvotes being an endorsement of me as a knowledge source rather than an endorsement of the ideas in the original answer.
Additionally, according to the help page on editing, edits are to be used for correcting minor mistakes or clarifications which do not change the meaning of the post. I believe the reasoning behind that is to address the above concerns.
Please treat the scope of this question as general, but the discussion was spurred by Fundamental question about dimensional analysis as suggested by dmckee.