Creativity is the key to developing teachers and pupils, head teachers were told.

Head teachers from the top 200 independent girls' schools in Britain were gathering in Brighton today for the second day of their annual conference.

In yesterday's opening speech Sue Singer, headmistress of Guildford High School and president of the Girls' School Association, said creative problem-solving could tackle teacher shortages and a busy curriculum.

In her address at the Grand Hotel, she called for less obsession with assessment and a reduced curriculum to allow for creativity.

Mrs Singer said: "My own vision is of a future in which neither pupils nor teachers are the slaves of an over-anxious examination system.

"The amount of external assessment could be significantly reduced if greater trust was placed in teachers and schools."

She said the fact that 40 per cent of new teachers left the profession within three years was alarming, but said it was not entirely due to money.

She added: "They need to be given the freedom to develop their ideas and those of their pupils, not forced into a tight assessment-led, work-sheet-dominated routine designed to cover an overcrowded and over-assessed curriculum."

Among the other speakers will be Lord Puttnam, chairman of the General Teaching Council.