While the news was positive in the academic scores, though, the study indicated much room for improvement in other areas, particularly the school environment.

Most worrying is the fact that Hong Kong students came bottom of the world in terms of their self-concept, and its schools bottom in how students value school life - 53 per cent agreed school had done little to prepare them for adult life, and 13 per cent said it was a waste of time.

Pisa is run by the Organisation for Economic Co-operation and Development (OECD) to monitor education systems around the world as children approach the end of compulsory schooling. It is specifically interested in how well they are prepared for adult life - the tests being based on the practical use of knowledge. It initially covered OECD countries, but an increasing number of others are joining.

Hong Kong was among 14 that joined in 2001, with its first results reported last year. Eleven more, including Taiwan, will take part in the next round, in 2006. By then the exercise will cover a third of the world's population.

The results are important for all the countries involved and could lead to extensive reviews of education systems. It gives them the opportunity to learn from each other as to why some succeed better than others in achieving what has become the holy grail of education, the magic combination of high standards and equitable opportunities.

Pisa operates through local centres. In Hong Kong, the Education and Manpower Bureau commissioned Chinese University's Hong Kong Centre for International Student Assessment, headed by Professor Esther Ho Sui-chu, to conduct the research.

The latest study should inform debates concerning the direction of Hong Kong's education reforms, from curriculum change and the allocation of school places to the need to invest more in early childhood education.

The 15-year-olds randomly selected across all types of schools to sit the two-hour tests in the summer of 2003 had not benefited significantly from reforms begun three years earlier. The academic results therefore indicate that there are key aspects of our education system that were already working well prior to the reform drive.

Education policymakers around the world will want to know how Hong Kong manages to not only top the tables in maths, but have a higher proportion of students performing above the OECD average than its competitors. It will be keenly compared with the top country in the study, Finland, which scored highest in science and reading and best balanced high performance and equity. South Korea also scored highly in all categories.

Hong Kong's results in maths and problem-solving are particularly significant as the focus of the tests was on how well students could use their knowledge in every day life. Rote-learning, according to the OECD, is associated with poorer Pisa performances.

But Professor Ho does not gloat over the achievements, and her centre stresses there was little statistical difference among the top countries in maths and science. Rather, she says, Hong Kong should build on its strengths and use the findings to identify and address weaknesses.

Hong Kong slipped from seventh to tenth in reading. Although it was still above the OECD average, she sees this as an issue that needs tackling, with the focus on how to create a better reading culture, not just in schools but the wider community. She would like to follow up on the Pisa research by studying how reading habits are changing.

Hong Kong is doing well in teaching basic numeracy and literacy skills, something many countries such as the United States are desperate to improve. But Professor Ho is concerned about the learning environment as indicated in students' responses in questionnaires accompanying the tests.

'We have a lot of room for improvement. We still have the lowest self-concept in the world.' She said this had to be tackled as it affected self-esteem of young people as they became adults.

Teachers today had too little time to focus on the more rounded education of their students. Parents also needed to be empowered with the knowledge and skills to participate more positively in their children's education.

Pisa analysed in detail the conditions that result in high achievement. Among the most significant globally was early childhood education. 'One or two years investment in early childhood education results in a huge increase in performance, which gives us direction to review our own investment in this sector,' Professor Ho said.

Pisa 2003 also sheds light on the role of private education. Overall, the study found those in private schools performed better, but that much of the advantage disappeared once the effect of social background of their students was taken into account. Better off families might, though, put more pressure on schools to improve and better teachers could be attracted as children were easier to teach.

In Hong Kong, Professor Ho found no difference in outcomes of students in private Direct Subsidy Scheme schools - mainly because most were low-cost private schools that had joined the scheme to benefit from public funding. Only recently have elite schools joined. International schools performed equally as well as local English-medium ones in the academic tests but had more positive school cultures than their local counterparts.

But the social segregation associated with private education is a matter of concern for both Pisa and Professor Ho. As more top local schools turn DSS and cater mainly for those who can afford their fees, others are denied opportunities, widening the equity gap.

Compared with other countries, there were extensive differences in performance between schools, reflecting the academic segregation that comes with Hong Kong's banding system. Finland, by contrast, managed to achieve high standards with more even performance across schools.

This raises questions as to whether Hong Kong should abandon the banding in its allocation of secondary places, the subject of a consultation due in the new year.

But Professor Ho warned that local conditions did not favour a comprehensive approach. 'Already we find teachers are working very hard to accommodate the greater heterogeneity of students since bands were reduced from five to three,' she said. 'They cannot absorb more.' An alternative way of narrowing the equity gap was to identify the disadvantaged schools and their problems and provide them with more resources.

According to the OECD, the best performing countries are those where 'students and schools perform better in a climate characterised by high expectations, the readiness of students to invest effort, the enjoyment of learning, a positive disciplinary climate, and good teacher-student relations.' They set an achievable target to aim for.

As for Hong Kong, many of these factors are in place, in particular in the strong academic culture. But as Professor Ho stresses, what it now needs is the care so that students are motivated by the fun of going to school and interest in what they are learning, not only the stick of the test.