Modern public-education history is littered with novel education theories that have failed so spectacularly that the terms are now used as pejoratives. For instance, when I was in elementary school in the 1960s, the "New Math" focused on teaching abstractions rather than fundamentals. You can find reams of research documenting its failure decades later, but the evidence was recognized almost immediately.
That then-new approach "ignored completely the fact that mathematics is a cumulative development and that it is practically impossible to learn the newer creations if one does not know the older ones," according to Morris Kline's 1973 "Common Core," a set of educational standards embraced by California and 39 other states in 2010. On hindsight, it also deserves a failing grade.
