I decided to cast a close vote on a question. Should I also down vote the question? When is it good practice to also down vote?
I'm happy about any feedback on this proposed answer.
It depends on many factors. For example on whenever you think the question is salvageable by editing. If you are able to edit the question to prevent the close vote, consider doing so. Editing is always the best solution.
But if the question is for example unclear, then cast the close vote and motivate questioner to add more information. A down vote is usually not necessary then.
Finally if the question has severe problems that are most likely not solvable, then consider to cast also a downvote with your close vote. Closed, negative score questions will automatically get deleted after 9 days. They don't have to go through the vote to delete process.
Background: Before 2013-08-05, certain closed questions received an automatic downvote from community. This process took care to keep AE's delete vote queue short by creating mostly negative score closed questions, but the behavior was changed.
Already asked on StackOverflow Meta:
EDIT #1: After Flow edited his question, my personal comment earlier is no longer relevant. However, I still agree on the Answer on the SO Meta posts above.
Generally, we should edit to make the question clearer. If it's lacking information, we ask for clarifications via comments. We ask them to edit that into their question, or we update it ourselves, based on their comments.
We can either be proactive or guide them to read the guidelines. But I prefer to be more proactive, as if I were gathering requirements from the customer. We ask in a way that we get what we exactly need to make it understandable for us and for everybody.
Regarding edits (and based on recent experience), chances are we may not always get it right. It happens. We're either too tired to understand / interpret it correctly (or it's not in our domain of expertise). OR, it could be that the question itself is too confusing to be rephrased. BUT, we can try to make it simpler and easier to read / understand. If our interpretation was wrong, the OP can always comment or improve our attempts to edit. This is peer review in action; we can't always be right.
When all else fails - meaning, the question is helpless - the VTC and downvotes come in.