How to assign partial credit on an exam of true-false questions?
There used to be a Decision Science class at Stanford, where this exact scheme was used. Students were warned all the time to never indicate 100% certainty on any question, because if you ever did that and turned out to be wrong, you would fail the entire course because of that one question: even if it happened to be a minor homework assignment. I always thought this was a great way to teach people the lesson that you should (almost) never claim 100% certainty in anything, and that you should view knowledge through a probabilistic perspective.