By how much did prep-ing/doing the SAT and AP prep book exercises improve your score?

Test Preparation
1

<p>I'm curious since I'm currently preparing for my SAT and I'm wondering how much the prep books actually help.</p>

2

<p>None...I dropped 90 points on the SAT after prepping. Not kidding. On the other hand, I went from a 180 PSAT sophomore year to a 222 junior year with no prep.</p>

3

<p>O.o NONE? </p>

<p>Scary.</p>

<p>Should I wait till the end of my Junior year to take the SAT or should I take it half-way through during October/December?</p>

4

<p>im doing the practice in october. and the real deal in the end. lets hope !</p>