A great teacher is critical to student achievement. So, how does a teacher become great? Just like the training required for any specialized profession, teachers must train. They must train before they enter the classroom, and they must receive ongoing training even as they work in the classroom. From college with certification coursework to student teaching to ongoing professional development (PD), teachers are continuously training during their career.
All this training gives new teachers the greatest chance of success as well as sustain veteran teachers as they meet new challenges in education. When this training does not happen, there is a risk that teachers may leave the profession early. The other concern is that when training is insufficient, students will suffer.