All school leaders want their teachers to have good-quality continuing professional development (CPD) that develops them as individuals and makes a measurable and significant contribution to school improvement. Clearly a number of challenges get in the way for many schools; budgetary and time restrictions being just a few. Furthermore, research from the Teacher Development Trust shows that, at present, the vast majority of CPD is having no impact in the classroom, and too few schools are bothering to check to see how, if at all, CPD is transforming teaching and learning.