This document discusses approaches to assessing teacher effectiveness. It outlines two basic approaches: evaluating what teachers do in the classroom and evaluating student achievement outcomes. The document also presents Charlotte Danielson's Framework for Teaching, which defines teaching practice across four domains: planning and preparation, classroom environment, instruction, and professional responsibilities. The framework provides a common language and structure for observing and evaluating teacher performance. The document notes challenges in implementing robust teacher evaluation systems and levers states can use to influence teacher effectiveness.