Moves to encourage teachers to work with each other to upgrade their skills will get a boost from a study funded by the Government and teacher organisations published next week.
It will show that teachers who work with their peers on professional development are far more likely to improve than those who take courses on their own.
The research review, led by a team from the Centre for the Use of Research and Evidence in Education, has also found that such collaborative professional development leads to better results in the classroom and usually better pupil behaviour. It also makes teachers more enthusiastic about training.
However, the team found little evidence that teachers who took training courses alone improved their practice or pupils' behaviour.
The review, chaired by Philippa Cordingley, chief executive of the centre, was sponsored by the General Teaching Council for England, the Department for Education and Skills and the National Union of Teachers.
The report says collaborative work should combine input from outside experts with peer support. It should involve experimentation and collaboration between teachers, preferably working in pairs or small groups, connected directly to the teachers' own classroom.
Where teachers take courses on their own, it suggests they should make the most of what they have learned by developing partnerships with colleagues and sharing experiences with them, or acting as coaches for other teachers.
This is the second review of research on professional development conducted by the team for the Evidence for Policy and Practice Information and Co-ordinating Centre (Eppi centre), based at London university's institute of education. It will appear on the Eppi centre website next Friday.
Future reforms to professional development will give pay rises to teachers who meet certain training standards and emphasise throughout the mentoring and coaching of colleagues.
The value of teachers supporting each other in training is one of the main themes in On Course, the special professional development supplement published with this week's TES.
On Course magazine inside this week's issue