The conference was reminded by the chief inspector with responsibility for leadership matters that 80 per cent of school and education authority leaders are found to be very good or good.
But Ian Gamble, HMCI, accepted that they face "a demanding agenda".
A key attribute of successful school leaders is that they have "a consistent impact on learning and teaching in schools, which is something they can do if they have a clear focus on that as the main business of what schools should be about".
Mr Gamble conceded that such a sustained impact is something school managers find very difficult because of the many other demands on their time.
HMI's guide to effective leaders is that they:
* Continually promote their vision in which learning and teaching is central.
* Involve themselves directly in the work going on in classrooms.
* Encourage debate on innovation.
* Seek out the best practice.
* Monitor and evaluate attainment levels in their school.
* Promote the school as a learning organisation for staff as well as pupils, "underlining the fact that everyone is capable of improving".
* Innovate carefully and avoid promoting change indiscriminately, doing so only where it can be sustained over time.