It's true that even modest improvements in teacher effectiveness can lead to impressive gains in student achievement. But what hasn't been clear is what exactly district leaders should do to encourage and support teachers in practicing the art and science of great teaching ... until now. Like in his landmark book "The Art and Science of Teaching", Robert Marzano and his co-authors once again make a definitive case based on extensive research. Find out what it takes to create a teacher supervision and evaluation system that's more apt to lead to higher student achievement, including: (1) Five school-level conditions that are essential to systematically developing teacher expertise; (2) Four domains of teaching practice that provide a focus for instructional improvement; and (3) Five ways to provide teacher feedback that avoids the pitfalls of a checklist approach. Going way beyond scripted observation routines and typical value-added measurements of teacher effectiveness, the authors open your eyes to broad principles of effective supervision that apply to all kinds of schools: (1) Why it's so important for teachers to have opportunities to observe and interact with other teachers; (2) Which types of assessments are most apt to provide evidence of student achievement gains; (3) Why recognition rather than money is more apt to motivate teachers to increase their expertise; and (4) How to engage teachers in focused practice that helps them chart their development in specific classroom strategies and behaviors.