This decision by the UC Regents (most of whom are political appointees) is counter to the recommendation of the faculty task force recently assigned to study standardized testing in admissions. It is obvious to anyone who looks at the graphs below that SAT/ACT have significant validity (technical term used in psychometrics) in predicting college performance for all ethnic groups.
See Report of the University of California Academic Council Standardized Testing Task Force for more.
... SAT and HSGPA are stronger predictors than family income or race. Within each of the family income or ethnicity categories there is substantial variation in SAT and HSGPA, with corresponding differences in student success. See bottom figure and combined model R^2 in second figure below; R^2 varies very little across family income and ethnic categories. ...
Test Preparation and SAT scores: "...combined effect of coaching on the SAT I is between 21 and 34 points. Similarly, extensive meta-analyses conducted by Betsy Jane Becker in 1990 and by Nan Laird in 1983 found that the typical effect of commercial preparatory courses on the SAT was in the range of 9-25 points on the verbal section, and 15-25 points on the math section."