States and districts have launched unprecedented efforts in recent years to build new feedback and evaluation systems that support teacher growth and development. The goal is to improve practice so that teachers can better help their students graduate from high school ready to succeed in college and beyond. These systems depend on trustworthy information about teaching effectiveness -- information that recognizes th complexity of teaching and is trusted by both teachers and administrators. To that end, the Measures of Effective Teaching (MET) project set out three years ago to investigate how a set of measures could identify effective teaching fairly and reliably. With the help of 3,000 teacher volunteers who opened up their classrooms to us -- along with scores of academic and organizational partners -- we have studied, among other measures:

• Classroom observation instruments, including both subject-specific and cross-subject tools, that define discrete teaching competencies and describe different levels of performance for each;

• Student perception surveys that assess key characteristics of the classroom environment, including supportiveness, challenge, and order; and

• Student achievement gains on state tests and on more cognitively challenging assessments. We have reported findings as we learned them in order to provide states and districts with evidence-based guidance to inform their ongoing work. In our initial report in 2010 (Learning about Teaching), we found that a well-designed student perception survey can provide reliable feedback on aspects of teaching practice that are predictive of student learning.

In 2012 (Gathering Feedback for Teaching), we presented similar results for classroom observations. We also found that an accurate observation rating requires two or more lessons, each scored by a different certified observer. With each analysis we have better understood the particular contribution that each measure makes to a complete picture of effective teaching and how those measures should be implemented to provide teachers with accurate and meaningful feedback. This final brief from the MET project's three-year study highlights new analyses that extend and deepen the insights from our previous work. These studies address three fundamental questions that face practitioners and policymakers engaged in creating teacher support and evaluation systems.