Idaho plans to adopt a new grading system for public schools while seeking a federal waiver to get around provisions of the No Child Left Behind education law.  Under the state Department of Education's new accountability system, Idaho will use a five-star scale to evaluate and recognize schools. The new measuring system would include standardized tests, graduation rates and student enrollment in advanced courses. Idaho is rejecting the latest requirements for determining school progress under No Child Left Behind. That policy is known primarily for its emphasis on standardized tests and the labeling of thousands of schools as "failures." Idaho and a handful of other states spearheaded a rebellion against No Child Left Behind last year, saying it sets unrealistic benchmarks and fails to accurately measure student growth.