>Being able to pass a test is indeed not a sign of mastery of the material I think/hope you mean "guarantee" rather than "sign", because, yes, someone who has

>Being able to pass a test is indeed not a sign of mastery of the material I think/hope you mean "guarantee" rather than "sign", because, yes, someone who has mastered the material is indeed much more likely to pass the test than someone who has not. The existence of non-representative counterexamples does not refute that.