How do you plan to measure this, exactly?
You don't measure it "exactly".
What are you demanding be measured? You measure enjoyment of the subject, and some general (low pressure, and non binding) tests on subject matter.
Come on, people. Science works. Things that work are...testable. If you're advocating some educational strategy, but reject the notion that it's testable, you're rejecting basic science.
I think you are confusing things. What are you wanting to test? The end of the year, high-pressure tests to measure "understanding" of the material, even if it crushes the spirit of the students?
You'd happily harm the education of the students, so long as it gives you a number that makes you feel better?
If that describes you, kindly keep your hands off education policy.
I think you are the one that needs to keep your hands off education.
Oh, and if you think what I suggested isn't "testable" then you are dumber than the chair I'm sitting on. I can think of 100+ ways to test it. They just don't work well as mass standardized tests given every quarter.