A single-sex school is a school that accepts boys or girls exclusively. This has been the traditional situation for independent schools, especially public schools and grammar schools in the United Kingdom, but many of these have now become coeducational. The number of single-sex state schools has fallen from nearly 2,500 to just over 400 in 40 years. According to Alan Smithers, Professor of Education at Buckingham University, there was no evidence that single-sex schools were consistently superior. In Hong Kong, where 10 per cent of schools are single-sex, girls appeared to do better. But in Belgium, where co-educational schools are in the minority, boys and girls who study together get the best results