In Michigan, 98 percent of teachers were rated effective or better under new teacher-evaluation systems recently put in place. In Florida, 97 percent of teachers were deemed effective or better. Principals in Tennessee judged 98 percent of teachers to be "at expectations" or better last school year, while evaluators in Georgia gave good reviews to 94 percent of teachers taking part in a pilot evaluation program. The data are also raising new questions about the observation components of the systems, which tended to produce the highest scores. Dozens of states have taken steps in recent years to overhaul their teacher-evaluation systems, often in response to federal incentives. Such changes have also been promoted by an influential lineup of organizations that calls for greater accountability in the teaching profession. The states hope to use the systems to strengthen teaching practices and dismiss poorly performing teachers.