All scientific research on this topic points to the conclusion that standardized test results are the single best predictor of subsequent academic performance. Some studies suggest that using GPA in addition to test results improves the prediction accuracy, but the marginal increase is very small, and it increases variance.

Everyone is well familiar with the downsides of standardized tests, but so far, nobody has proposed any alternative that better. Learning to the test is not great, but what’s the alternative? It’s not like anyone knows how to teach things that results in more actual knowledge and skills being attained despite lower test results.