Suppose a new user makes a first stab at writing an answer, but to a more experienced user's eye, his contribution would be more appropriate as a comment. The canned response offered to reviewers is
This does not provide an answer to the question. To critique or request clarification from an author, leave a comment below their post - you can always comment on your own posts, and once you have sufficient reputation you will be able to comment on any post.
If I put myself in the shoes of a new user, this is as frustrating to hear as the dentist's non-yes-or-no question when he's just stuck a bunch of tools in my mouth. I want to cooperate, delete the answer, and put my text into a comment -- but I can't.
Assuming that creating frustration is not our actual goal here...
When a new user (with insufficient rep to comment) writes a dud answer on his first time out, what is the most desirable behavior we would like to elicit from the new user?
Delete the answer and try harder to write a real answer, perhaps for some other question.
Improve the answer through more thought and research, better documentation, and figuring out where the "Edit" button is.
Leave the answer as is, but feel stymied, put down, embarrassed, annoyed, etc. -- in short, something negative.
None of the above?
-- Edit to clarify --
Please note, this question is different from the one referenced above. (That one asks, what action should reviewers take to deal with dud first answers.) This question asks you to back up a step and figure out what you would like to see happen after the dud answer has been submitted and reviewed.