In Teaching Matters Most, Thomas McCann, Alan C. Jones, and Gail Aronoff make the case that the single most important factor in continuous school improvement is the quality of instruction in schools. Unlike other books that stop at evaluating teachers and instruction, these authors argue that school leaders must work to grow the instructional capacities within their schools. To meet this goal, they offer school leaders a three-step process that involves: (1) envisioning what good teaching looks like (2) measuring the quality of current instruction against this standard, and (3) working relentlessly to move the quality of instruction closer and closer to the ideal.