<p>I wasn't trying to challenge the validity of your evidence. Let's assume the study is perfect, because it obviously has a large enough sample size to be close.</p>
<p>Anyway, in the study you cited, the coefficients of determination for the SAT Subject tests and high school GPA were really not significantly higher than the coefficient of determination for the SAT Reasoning test. I sympathize with your point, but I'm asking for a reason why the alternatives are better, because from those numbers (.128 versus .153 and .145), the alternatives you posited don't seem to be any more desirable.</p>