A principal's most important role is instructional leader. There is a growing recognition of the importance of working with teachers, serving as a mentor and coach. Coaching has emerged as one of the more effective professional development options for adult learners. It is an important tool because it is an investment in human capital and in the systemic improvement of individual teachers and their school. Instructional coaching provides individual teachers with one-to-one assistance working on identified instructional needs. It is an improvement model based on the belief that teachers, given an opportunity, can diagnose their own teaching and identify ways to strengthen their work. Coaches help teachers identify the focus and then work with them to reflect on and improve their practice. Coaching can serve as a school-wide school improvement strategy. Because its focus is on the core work of teaching, it supports a culture of collaboration. Principals hold two roles--evaluator and coach. While evaluation is necessary, there is increasing recognition of the importance of coaching. Coaching is a change from traditional roles. The primary role of the coach is to ask questions that are open-ended and promote cognition. Listening, probing for deeper meaning, and being non-judgmental are critical skills. Good coaching is built on a foundation of trust. It occurs when the coach creates a open, respectful and inviting setting. Coaching cannot be forced. Good coaches share several traits. They: (1) Enroll teachers; (2) Identify Teacher Goals; (3) Listen; (4) Ask thoughtful questions; and (5) Provide feedback. (Contains 5 online resources.)