NCTQ has been tracking teacher policy for a decade. Over these years, no policy has seen such dramatic transformation as teacher evaluation. It hasn't been an easy road for states. The simultaneous implementation of teacher effectiveness policies and the Common Core, along with the transition to new college- and career-ready assessments, have almost every state in the country in flux. The pressure is on to curb state testing and roll back teacher evaluation policies.

But for now, we remain optimistic that states will stay the course and build on their efforts around teacher effectiveness. NCTQ's new report released this week, State of the States 2015: Evaluating Teaching, Leading and Learning, presents the most comprehensive and up-to-date information on how states are evaluating teachers and using those results to inform policy and practice. The report also breaks new ground by providing a first look at the policy landscape on principal effectiveness.

What is clear is that teacher effectiveness policy has a strong foothold in state policy – and that's important to its endurance. In 2015, 43 states require that student growth and achievement be considered in teacher ratings and in 35 states evaluations of teacher effectiveness are significantly or mostly informed by student growth and achievement. Twenty-three states require districts to factor teacher performance into tenure decisions.

Only three states NCTQ once recognized for having developed teacher effectiveness policies (South Carolina, Utah and Wisconsin) no longer appear to require student growth and achievement to be a significant factor in teacher ratings. Today there are just five states (California, Iowa, Montana, Nebraska and Vermont) that have no formal state policy requiring that teacher evaluations take objective measures of student achievement into account in evaluating teacher effectiveness. ESEA waivers haven't been the policy driver some think they've been; most state action happened before waivers came on to the scene. And most later on the scene states have enacted state policy too. In fact, only Alabama, New Hampshire and Texas have teacher evaluation policies that exist only in waiver requests to the federal government.

In our first survey of the principal evaluation landscape, we identified 34 states that require annual evaluations of school leaders. In most cases the requirements for how student achievement and other factors are weighed in principal ratings mirror the requirements for teacher evaluations. Still, principal effectiveness seems often to be an afterthought in many states. Many states do not specify who is responsible for conducting evaluations of principal effectiveness, don't require observations of school leaders doing their jobs and don't require training and/or certification for principal evaluators. New Jersey is a notable exception in requiring principals to be evaluated on the quality of the teacher evaluations they oversee.

While the evaluation policy landscape has been transformed, much work remains on implementation. Some states and districts have had and are continuing to learn the hard way that some practices are ill advised (Using schoolwide data only to measure student growth for teachers of non-tested grades and subjects and requiring tests that serve no instructional purpose but to provide teacher evaluation data are two that readily spring to mind). As we've argued all along, the real power in performance-based evaluations lies in using the results to recognize and encourage effective instruction as well as to prepare and value highly-effective teachers and leaders. And states are increasingly making some of these critical links, turning what was once a bureaucratic exercise into a more meaningful process with the potential to continually improve teaching and learning.