EDIT: As my experience with the site has grown, my views on how to deal with low quality answers have also changed. My complete old answer can be found in the edit history; I believe that rewriting my answer in this manner is not a problem in this case since it did not receive any votes originally.
The SE model is, in short, that:
- Good answers get voted up and rise to the top.
- Bad answers get voted down and fall to the bottom.
- Off-topic posts get removed.
So, with this model in mind we should:
downvote answers such as A1 and A2,
delete answers such as A3, and
upvote answers such as A4.
More generously, we should additionally comment on answers like A1–A3 to let the authors know about our site norms, because such answers are usually given by newcomers who do not yet know our ways. Here is an easy way to add templated comments.
If it's possible to salvage such answers, then we should edit to improve them, because that not only helps us maintain our site, it is also another way of educating the poster about the quality we expect in our answers.
My old answer ended much as above. Now with more experience I realise that this answer was incomplete for the following reason:
Many (in fact most) users who post low quality answers are one-time visitors to our site. Having found a question of interest through Google, they drop an answer with an unregistered account and then do not return. This means that the feedback we give them on answers like A1 and A2 via downvoting and commenting are not of use to them. So, such low quality answers persist, which is not a good thing.
Hence, I propose that in addition to the above steps, we should:
follow up on low quality posts to see if they are improved by the OP. This means that
if the OP does not return to the site within a week, or does return but makes no attempt to improve the answer, then we should flag the answer as VLQ. Note that the VLQ flag is only available on an answer for a week from the date it is posted.
The volume of activity on our site is currently small enough that it is easy to keep track of new posts for up to a week, so this should not be a problem.
What about for older low quality posts that have not been removed? For them I suggest that we should
comment and downvote, so that attention may somehow be drawn to the OP. Many times the user happens to be active on other sites on the SE network, so when this is the case they notice the ping and return to improve the answer.
If this does not draw their attention within a week, and the answer is not salvageable by editing, then flag it as NAA. Most low quality answers of the kind A1 or A2 are usually more fitting as a comment, and this is a use case that comes under the NAA flag.
These are my thoughts on how to handle low quality answers. Any thoughts and feedback are appreciated.