TITLE What Differentiates an Excellent Teacher from a Teacher

This study examined what teachers needed to learn to teach in new ways and how teachers developed those capacities. It also investigated the additional skills and orientations teachers needed to take on leadership roles and how teacher leaders acquired their ability to lead their colleagues. Data came from a 2-year study of 10 exemplary teacher leaders who had played significant roles in their districts ' and states ' standards reform initiatives. Results indicated that ongoing, high quality professional development experiences played an important role in their careers. Their ability to collaborate with peers and to become more reflective practitioners was enhanced by powerful professional development. These experiences also expanded their professional networks. At the end of the 2-year data collection, the 10 teachers met to discuss the findings. During the discussion, they examined what differentiated excellent teachers from teacher leaders. Besides high levels of expertise, collaboration, reflection