Tom Kane has tracked years of U.S. test scores. Here’s what he’s learned — and still can’t explain.

Tom Kane, a Harvard University professor, analyzed U.S. test scores and found declining student achievement since 2013, particularly in reading, with partial recovery in math but not reaching pre-2013 levels. His research highlights theories like reduced test-based accountability and increased social media use but lacks definitive answers, while middle-income districts show the most reading score declines.