BearCam said:
What you wrote is precisely the opposite of what Dartmouth found. To quote the NYT:
"Three Dartmouth economists and a sociologist then dug into the numbers. One of their main findings did not surprise them: Test scores were a better predictor than high school grades or student essays and teacher recommendations of how well students would fare at Dartmouth. The evidence of this relationship is large and growing."
As it turns out, test scores are one of the best predictor of success in college relative to other measures provided by students to the universities.
The issue is the statistical analysis of these tests. They are not valid predictors of any outcome (criterion-related validity). That is, they were not developed using statistical tests of these tests. These tests do not purport to correlate their scores with any other quantitative value, such as frosh gpa, successful graduation, gpa at graduation, etc. They only provide a clean ranking of the test takers on that date. Any desired statistical analysis can then be done against population subgroups such as age, region, race, gender, etc. Such analyses probably showed results that were not desired, therefore they were dropped. Now, there is probably no criterion on which colleges can rely, because as the deterioration of their quality, i.e. hs education, there is nothing on which they can rely.
The best test is a test of moderate difficulty for the target population. You want discrimination, but discrimination on the desired prediction criterion. A too-difficult test will fail even those who can perform on the desired criterion, i.e. making it past the frosh year, say. A too easy test is a waste - it doesn't discriminate between those who can and those who can't. Same with the value of a degree - pass all students and the degree signifies nothing; flunk everyone out and no one gets your degree.
What Dartmouth has concluded is that they need something and given the changes in the ed system, the SAT is the best we've got now, despite its failings. They cculd go with a series of interviews, in-person performances, and pre-entry academies, but those would be too expensive.