According to an Ed Dept press release:
In his speech, Duncan said that the NCLB law has significant flaws and that he looks forward to working with Congress to address the law’s problems. He said the law puts too much emphasis on standardized tests, unfairly labels many schools as failures, and doesn’t account for students’ academic growth in its accountability system.
“But the biggest problem with NCLB is that it doesn’t encourage high learning standards,” Duncan said. “In fact, it inadvertently encourages states to lower them. The net effect is that we are lying to children and parents by telling kids they are succeeding when they are not.”