I think it would a good idea to have a checkbox saying that "this is a homework question" possibly next to I want to answer my own question part. It would be good reminder for people to state it. New users don't know they are supposed to state they are asking homework questions by taging the question with homework tag. I saw lots of "is this a homework question" comment in stackoverflow, that is why I think stackoverflow could use something like this. Maybe it can be coupled with Add a Short Message above the Answer Box when the [Homework] Tag is Present for an greater usefulness.
What good does knowing it's a homework question do? If the question is well formed, shows effort by the OP, and doesn't ask someone to do their work for them, it will likely get answered.
If not, it will be closed until the OP can correct the issues with the question. This is true whether the question is homework or not.