A growing chorus of education policy advocates is urging the U.S. Department of Education to strengthen graduation-rate accountability in states that have earned waivers under the No Child Left Behind Act ... "What's most concerning is the number of states and the variety of ways in which graduation-rate accountability is being implemented that is different from graduation-rate accountability as envisioned under the 2008 regulations," said Phillip Lovell, the vice president of federal advocacy for the Washington-based Alliance for Excellent Education, which works on high school issues and signed on to the September letter.