I hadn’t thought of this effect, but it’s kind of an ingenious way to market test prep. I think at some point, students’ scores stop improving, from a combinati

I hadn’t thought of this effect, but it’s kind of an ingenious way to market test prep. I think at some point, students’ scores stop improving, from a combination of having been exposed to all the background material necessary for the test to be accurate, and their brains finishing development (after which intelligence is largely stable), but up until then, students’ scores improve with age. You can still use a test like the SAT to compare younger students, but you have to norm it against students of the same age (I think it’s actually better to test students at a younger age because a test of the same difficulty has more ceiling room).