A lot of people are using the "answer" part of an already existing question to ask a new question instead of creating a new one.
They probably find the question with google and post their question here, thinking Stack Exchange is a regular forum.
How to make sure they understand how SE works before asking a new question ? Should we make "taking a tour" a mandatory step, with a few (3 or 4?) questions at the end to make sure they read it ?