Stephanie Banchero & Arian Campo-Flores:

Millions of students heading back to school are finding significant changes in the curriculum and battles over how teachers are evaluated, as the biggest revamps of U.S. public education in a decade work their way into classrooms.
Most states are implementing tougher math and reading standards known as Common Core, while teacher evaluations increasingly are linked to student test scores or other measures of achievement. Meantime, traditional public schools face unprecedented competition from charter and private schools.
Supporters say the overhauls will help make U.S. students more competitive with pupils abroad. But others worry that the sheer volume and far-reaching nature of the new policies is too much, too fast. Already, the changes have sparked pushback.