“Personal opinion” then.....
No, just a reasoned conclusion. You asked, “do you have something that you can post to back up your claim?” What we already know is enough to point up the absurdity of grades and tests, once we examine it without the official “instructors” guiding us.
If taken at face value, the whole system is absurd. I mean, does it really take 14 years to learn the stuff a high school graduate knows?! LOL! That’s just ridiculous. No, there’s more behind “schooling” than teaching kids to read, write, and do simple math.
So if you’re waiting for Big Ed to publish a study demonstrating the practical uselessness of standardized tests, better grab a cup of coffee and get comfortable...You could be waiting a while.