A state law, which helped Tennessee win Race to the Top money, pushed schools to implement a system that had limited pilot-testing. Education officials in Tennessee are taking flak from teachers and unions for rushing the implementation of the new teacher-evaluation system that will eventually undergird tenure decisions--a move, some worry, that could undermine redesigns of evaluation in other states. The new system, as defined in the law, bases 50 percent of a teacher's evaluation on observation ratings, 35 percent on student-growth measures, including value-added data, and 15 percent on other measures of student achievement. For teachers whose subjects and grade levels are not tested, the state can approve alternative student-growth measures. The evaluation system is also tied to a new teacher-tenure process, under which teachers must teach for five years and receive high evaluation ratings in the final two years of teaching before being eligible for tenure. But many teachers are already frustrated, primarily with the extensive lesson planning needed to score well on the observational measure.