And even though most states require school districts to offer at least half-day kindergarten, only 17 states and the District of Columbia mandate that children attend it. Only 14 states and Washington, D.C., require districts to offer full-day kindergarten, according to kindergarten policy data collected by the Education Commission of the States, a national think tank. But state policy has been slow to catch up with this point. It’s also a fact - true, true, true, and we can prove it - that full-day kindergarten classes like Lemoine’s help kids do better in early elementary school, researchers say.
