How do you measure knowledge/learning? I suppose if you take a test a PASS/FAIL would indicate that. But C- is a passing grade as is A+. I liked the comfort of knowing what I knew and what I didn't know by being graded and learning what I got wrong. Just like a Driver's Test. There is pass or fail of course BUT there are standards. You can only miss so many and then you fail the test. You are shown what you got wrong. If you fortunately get all of them right you get 100%! How do you feel about grades? Why?