For one, Pisa has shown that rote-learning and hours of tuition do not work.

The top placings of East Asian nations, including Singapore, were initially attributed by some detractors to rote-learning and the many hours of tuition that Asian students receive outside school hours. However, Pisa has shown no positive correlation between tuition and performance. (..)

It's also not about money. Pisa studies comparing student scores with spending per student explain only about less than 20 per cent of the performance variation among countries. Also countries with similar spending achieve very different results. Pisa results also show that parents sending their children to private schools are wasting their money. In countries where a substantial proportion of students attend private schools, pupils in public schools score lower in science than students in private schools. But this is not the case once you take into account the socio-economic background of the pupils.

Parents here and in many other Asian nations clamour for smaller class sizes, but Pisa data again shows that it is not about smaller class sizes. The top-performing East Asian nations have larger classes.

NO HIGH-TECH ADVANTAGE

Another useful insight from the Pisa data: computers and classroom technology do not improve student performance.

The study, done last year, found "no appreciable improvements" in reading, mathematics or science in countries that invested heavily in information technology. In fact, the frequent use of computers in school is more likely to be associated with lower marks,

Of the seven territories that had the highest levels of Internet use in school, three - Australia, New Zealand and Sweden - were found to have "significant declines" in reading performance, while another three - Spain, Norway and Denmark - had results that had "stagnated".

The territories with the lowest levels of Internet use in school - South Korea, Hong Kong and Japan - are among the top performers in international tests.

In Singapore, students who reported that they "never or hardly ever" browse the Internet for schoolwork in school, performed the best in the digital reading test. They scored more than 30 points better than students who reported browsing the Internet in school "at least once a week".

Similarly, students who reported that computers are not used in maths classes scored the highest in the computer-based maths test.

So, what counts in raising standards?

TEACHERS, ENVIRONMENT MATTER

What six cycles of Pisa data have also shown is that the quality of teachers and the learning environment matter. Also, in top-performing countries, importance is placed on education.

Pisa officials have noted the high expectations that Asian parents and teachers have of their young charges. There is also a strong belief that all children are capable of success and education will help them achieve success.

Pisa surveys on student attitudes in learning mathematics, for example, have shown that student attitudes and motivations matter. Students who believe that they can improve their mathematics skills through more practice and effort tend to do better in the subject than students who put it down to innate ability.

As Dr Schleicher told The Straits Times: "Students in North America would tell us that talent counts. If I'm not born a genius in maths, I'd better study something else. But the majority of students in Asian countries such as Singapore would say that it depends on how much time they spend, and how much effort they put in. "So for them, their achievement depends on how much time and effort they put in, rather than inherited intelligence, which suggests that education and its social context can make a difference in instilling values that foster success in education."

STREAMING AT LATER AGE

There is another Pisa finding that is significant for Singapore in the light of the debate on PSLE.

Although the MOE has announced changes to the PSLE scoring system to reduce the competition and stress, many have asked if children as young as 12 should be subjected to a high-stakes examination - and one that routes them into different paths in secondary school, at that.

Singapore, despite its high scores, should look to Estonia, Finland and Canada. Many here have suggested routing students into technical or academic paths at age 15 or 16 instead. These countries show that streaming children into academic or vocational streams may work better at a later age.

Pisa has also found that when pupils are diverted from academic tracks at an early age, whether towards a vocational school or a less rigorous stream, it widens the gap between rich and poor children.

Take the Netherlands, for example. Pupils at its vocational schools have results equivalent to about three years less of schooling than their peers at general schools.

South Korea has also made huge strides in education, by incorporating technology into classrooms. In the 1990s, the country launched a master plan to provide every teacher with a computer and every classroom with internet access. In 2005 it launched a “Cyber Home Learning System” that gives students home access to digital tutoring. Then in 2011, it plowed $2.4 billion dollars into digitizing the country’s entire school curriculum by 2015. By then, South Korean students won’t be using traditional textbooks, they’ll have interactive ones with content that can be continually updated. In the 2012 PISA rankings, Korean students ranked 5th in math and reading and 7th in science. Not bad for a country that, not long ago, was considered a developing one.

(..)

Back to Mr. Schleicher. At the age of ten, he was doing so poorly in German public school that his teacher found him ‘unfit’ to move onto an academic secondary school. Furious at the prospect his son would be streamed into vocational training, his father pulled him out and enrolled him in a private Waldorf academy, where he thrived. He earned top marks on his entrance exams to college, and went on to study physics and mathematics.