This piece describes the widely held perception among education leaders that we already know how to help teachers improve, and that we could achieve our goal of great teaching in far more classrooms if we just applied what we know more widely. Our research suggests that despite enormous and admirable investments of time and money, we are much further from that goal than has been acknowledged, and the evidence base for what actually helps teachers improve is very thin.
Jacob, A., & McGovern, K. (2015). The mirage: Confronting the hard truth about our quest for teacher development. Brooklyn, NY: TNTP. https://tntp.org/assets/documents/TNTP-Mirage_2015.pdf.