http://www.nytimes.com/2011/12/25/sports/before-athletic-recruiting-in-the-ivy-league-some-math.html
Before Recruiting in Ivy League, Applying Some Math
By BILL PENNINGTON
New York Times
December 24, 2011

According to http://www.nytimes.com/imagepages/2011/12/25/sports/25ivy-GFX.html?ref=sports the academic index is computed using either
(1) SAT scores and the GPA OR
(2) SAT and SAT II scores and the GPA

There is a minimum academic index for recruited athletes. The Ivies have discretion in how much weight they give the academic index for other students.

"To see what is in front of one's nose needs a constant struggle." - George Orwell