Standardized tests versus grades

Sent to the Seattle Times, April 27.

Randy Dorn claims that "Testing can tell if students need help before college and career," (April 27).
I wonder if Mr. Dorn is aware of research evidence showing that high school grades in college prep courses are an excellent predictor of college success, and that standardized test scores (the SAT) do not provide much more information than grades alone.
Is there any evidence that the Smarter Balanced Tests are a better predictor than grades?

Stephen Krashen


Original article: http://www.seattletimes.com/opinion/testing-can-tell-if-students-need-help-before-college-and-career/
 
Sources:
Bowen, W., Chingos, M., and McPherson, M. 2009. Crossing the Finish Line: Completing College at America's Universities. Princeton: Princeton University Press.
Geiser, S. and Santelices, M.V., 2007. Validity of high-school grades in predicting student success beyond the freshman year: High-school record vs. standardized tests as indicators of four-year college outcomes. Research and Occasional Papers Series: CSHE 6.07, University of California, Berkeley. http://cshe.berkeley.edu