The exams were typically essay-ish (even in science classes) where you either had to basically reiterate the reasoning for a fact you already knew, or use similar reasoning to establish/discover a new fact (presumably unknown to you because not taught in class).
Unfortunately, it didn't work for me and I still have about the same critical thinking skills as a bottle of Beaujolais Nouveau.
It is however not taught very well by some teachers, who skirt on explaining how to properly do it, which might be your case.
I also don't see what's "on the contrary" there.