There are a number of papers making related claims. The typical conclusion is: test prep helps, but paying for test prep is only marginally better than self study.
For some strange reason they are often summarized as "test prep had no effect".
For some strange reason they are often summarized as "test prep had no effect".
But yes. If only because of the time constraints of the test (and it's more than that), sitting down and taking the SAT cold would be really hard for most people without prior exposure to similar tests. Heck, I'm pretty sure I couldn't today. I'm guessing I would do pretty well on verbal but too much of the math would be way too far in the past. And I wouldn't have time to derive formulae even if I remembered enough first principles to do so.
Test prep certainly helps. Knowing that test prep helps is key knowledge that is suppressed by these studies. Having the time to engage in test prep is often a luxury. Having the skill and discipline to do effective test prep is a lot to ask.
This is part of what colleges are selecting for.