Finland's claim to have the best school system has been reinforced by the latest international comparisons.
Finnish pupils spend the shortest amount of time in lessons
First results from the PISA study of 40 countries put it top overall in the maths, reading and science tests.
PISA is a three-yearly appraisal of 15 year olds in the principal industrialised countries, organised by the OECD economic grouping.
The UK as a whole was excluded for failing to provide enough results, though Northern Ireland did well.
PISA - the Programme for International Student Assessment - aims to assess the knowledge and skills needed for full participation in society, rather than mastery of a curriculum.
It compares Organisation for Economic Co-operation and Development (OECD) member nations and "partner countries" and regions, such as Russia and Brazil.
The 2003 PISA study focused on mathematics
The tests were taken by more than a quarter of a million students, representing about 23 million in the participating countries.
The focus of the 2003 study was mathematics, with problems mainly set in real-world situations, covering space and shape, change and relationships, quantity and uncertainty.
Hong Kong had a slightly higher mean score than Finland but on overall proficiency, Finland came top, ahead of South Korea then Canada, with Indonesia bottom.
The OECD used seven proficiency levels in increasing order of skill, from "below Level 1" to Level 6.
Half or more of the 15-year-olds reached at least Level 4 in Finland, South Korea and Hong Kong.
BEST MEAN SCORES: MATHS
Hong Kong-China: 550
South Korea: 542
Source: OECD PISA 2003 data
In Mexico, only 3% did so - with an even lower percentage in Indonesia and Tunisia.
In most countries that are members of the OECD, at least three quarters of students reached Level 2 - but more than a quarter were unable to complete those tasks in Italy, Portugal and the US.
"These students fail to demonstrate consistently that they have baseline mathematical skills," the report said.
The authors caution that - in line with previous international comparisons - only about one tenth of the variation in student performance on the overall mathematics scale lies between countries.
Most is within countries - between education systems and programmes, between schools and between students within schools.
SAMPLE MATHS QUESTIONS
Have a go at some of the problems the students were asked to tackle.
For example, in Belgium, mean scores on the maths scale for the Flemish community were higher than those in the best-performing OECD countries, Finland and South Korea.
Results from the French community, however, were at the OECD average.
Both Germany and the Republic of Ireland scored near to the OECD average but the range of performance within Ireland was one of the narrowest, while the difference between the 75th and 25th percentiles in Germany was among the widest.
In "reading literacy", the overall results found Finland, South Korea and Canada at the top, and Indonesia again bringing up the rear.
On the science scores, four entrants had statistically indistinguishable high average performances: Finland, Japan, Hong Kong-China and South Korea.
BEST MEAN SCORES: READING
South Korea: 534
The OECD report also considers gender differences.
In maths, it said much remained to be done to close the gap which saw boys outperforming girls.
In reading, girls had "significantly higher average performance" in all countries except Liechtenstein. The biggest gap was in Iceland.
BEST MEAN SCORES: SCIENCE
Hong Kong-China: 539
South Korea: 538
Science showed the smallest average gender gap, with boys doing a little better.
Girls performed significantly better than boys only in Finland, Iceland and Tunisia.