WASHINGTON (AP) — The Republican-controlled Senate education panel is beginning its revision of the landmark No Child Left Behind education law.

It’s focusing first on the thorny issue of federally mandated testing of America’s schoolchildren.

The law mandated that states annually test in reading and math for grades three to eight and once again in high school. Critics say that mandate has led to a high-stakes testing culture and teaching to the test. But supporters say the testing is an important way to track student learning.

Republican Lamar Alexander of Tennessee leads the Senate’s education committee. He says he’s open to listening to all sides of the testing debate.