[jonnathanson]

This is spot on, and in theory, it's why standardized testing was implemented in the first place: to get at normative ways to compare knowledge in a given subject across schools and learning environments. It was social engineering, really: by convincing schools that their students would be held accountable to universal standards, those schools would in turn up their games and make sure students were learning the real deal.

Of course, what actually happened was twofold:

1. "Teaching to the test," i.e., narrowing a broad subject area like Calculus down to whatever aspects would be covered on a standardized AP exam.

2. Following from the above, a reduction in foundational and principle education in favor of problem-based education. Kids would learn the what of the formulas, but not the why. Kids could calculate a derivative, but they couldn't tell you what it meant or why they would ever need to do so.

The result? A vicious cycle. Subjects narrowed and became divorced from their foundational purposes, which accordingly made them more about rote than about thinking, which made them less engaging subjects, which in turn discouraged student interest, which in turn led to declining scores. And the cycle repeated itself.