As far as schools and how they take in the tests there are a lot of different ways. There are schools where these tests are optional, more than you may think. You are probably too early in the identification of schools to see if they don't require the tests so its probably best that you do take the SAT or ACT. Schools can not find out your results though unless you send them (unless I missed something....). My general impressions are that most schools that require ACT or SAT will super score the SAT and some super score the ACT. What super score means is they take the best results from different tests and put them together - for instance if on your first SAT you get a 600 reading/writing and a 650 math and the next time you take it you get a 650 reading/writing and a 600 math, then each individual test score totals a 1250 but the super score would be a 1300 - 650 Math from 1st test and 650 reading writing from 2nd test. Holy crap that was a run on sentence.... You can take these exams as many times as you want and just pick the two tests to combine to super score. Since your son is a sophomore he will get the opportunity to take practice exams. I suggest he try's both exams and if you all agree one seems to work better for him start focusing on that one. Get this part down first and then later on you can start focusing on D1 or D3 talent but scores will matter more for D3 in my opinion.