Although I also think it’s dangerous to rule out the value of test prep — with one very important caveat: the test itself has to be legitimate and valuale. If what’s being tested is actually substance and skill, there’s no problem with teachers teaching that substance and skill. It’s when the tests themselves don’t measure what’s supposed to be happening in the classroom, but instead measure how well students can fill in bubbles or rule out obviously wrong answers, that test prep becomes a totally vapid exercise.