Mike Kent is right - continuing professional development is very important ("Hit and miss is par for the course", May 14). It's about investing in teachers for the benefit of pupils, and it's what we do in the Science Learning Centres, day in and day out.
But how much of the available CPD is subject-specific? The vast majority of what goes on in primary and secondary schools and colleges is about teaching subjects, be they science, history, music or whatever, and that is at the heart of teachers' professionalism.
Get the subject teaching skills right and most of the other important things - such as behaviour - will follow.
Professor Sir John Holman, Director, National Science Learning Centre, York.