There is no shortage of research on the importance of good teaching. For decades, study after study has shown that there are large differences in effectiveness from one teacher to another and that these differences can have a lifelong impact on students. A recent study that tracked 2.5 million students over 20 years determined that those with…

Experience makes a difference--especially at the beginning of a teacher's career. On average, teachers with some experience are more effective than brand new teachers. Teachers improve the most early in their careers. One study found that "close to half of the teacher achievement returns to experience arise during the first few years of teaching."…