HARTFORD, Conn. (AP) Connecticut has been given another year by federal education officials to work on school changes, including teacher and principal evaluation.

The U.S. Department of Education announced Thursday that it approved a February request by Connecticut officials to extend for one year a waiver from some provisions of No Child Left Behind. Waivers also were granted to Arkansas, Colorado, Nevada, South Dakota and Virginia.

Federal education officials said Connecticut's waiver has helped schools improve student achievement and that the waiver may be renewed.

U.S. Education Secretary Arne Duncan said Thursday the waivers have allowed states to be more innovative.

Connecticut's waiver, first announced in May 2012, gives the state more flexibility to spend federal money and it avoids having to declare nearly half the state's public schools as failing.