Is it preferred to edit another user's answer into completeness, or to create a similar answer?

Question

If, after some personal investigation, I find that my own answer to a question overlaps an existing answer by "85%" or so, is it preferred that I edit the existing answer? Or, is it preferred that I provide a new answer that is 85% similar (not word for word, but in meaning) to an existing answer?

Any difference if the question is mine versus not mine?

Answer 1

Here's my mental flow chart:

• Am I excited about writing an answer in my own words?

  • Yes?

    Then write my own answer and acknowledge the overlaps either in a comment or somewhere inconspicuous in your answer.

  • No?

    • Can I reference my additions in a comment?

      • Yes?

        Simply comment and optionally offer to edit in the additions if the author cares to include them.

      • No?

        Submit an answer that fills in the details you'd like to add. Optionally offer to edit the additions into the other answer.

Personally, I think editing should be primarily limited to correcting minor mistakes, adding supporting links, cleaning formatting, etc. If you have an entire new point to suggest in answer, I think you ought to provide an alternate answer. Because I sometimes feel the need to write about something, I occasionally submit an answer without reading the existing answers. It's a bit of a case-by-case judgement call, in my opinion.