1) The document summarizes research on teacher effectiveness and implications for teacher professional development. It finds that teaching skills can be grouped into 5 developmental stages linked to student outcomes.
2) A study is described that validated these 5 stages and found teachers in higher stages were more effective.
3) The document proposes a dynamic approach to teacher training combining skill development tailored to teachers' stage with guided reflection, in contrast to traditional competency-based or holistic approaches.
4) A project found the dynamic approach improved teaching skills and student achievement more than the holistic approach, showing the value of focusing teacher development on their specific needs.