Saw someone tweet a few weeks back that criteria for advancement in education (e.g., graduating 1st to 2nd grade) needs to be mastery-based, instead of time-bas

Saw someone tweet a few weeks back that criteria for advancement in education (e.g., graduating 1st to 2nd grade) needs to be mastery-based, instead of time-based. This is the most brilliantly simple insight into our education system I've ever come across. What better way to make someone feel 'dumb' than to give them an "F", "D", or "C" after a year of education when their peers receive "A"s and "B"s.