And so it begins. Even before the Programme for International Student Assessment 2015 results were published, my Twitter feed was crammed with debate about Pisa; including from those who think we can effortlessly transfer the excellent results from the high-performing Far East nations to places such as the UK, and from those who view international comparisons as yet another stick with which to bash teachers.
Then there are those who, like me, think we can learn a lot from global comparisons, as long as we take the time to absorb the context and accept that there are rarely any simplistic short cuts in trying to secure long-term improvements in education standards.
And Pisa gives us lots of context. It isn’t just a league table of high- and low-performing countries.
In fact, it isn’t even that – many countries that score highly in raw attainment often have large inequalities between rich and poor pupils, or between the highest and lowest performers.
The Organisation for Economic Cooperation and Development, which runs Pisa, goes to great lengths to stress the fact that context matters – alongside the "league tables" published in Pisa today are valuable insights into how different countries approach teaching and how they structure and resource their school systems.
In preparation for hosting the global launch of the Pisa 2015 results this week, I spent some time pouring over the embargoed reports of the weekend.
There is a wealth of data to be mined (and there are still three further volumes yet to be published), giving researchers and policymakers plenty to chew over until the next round of Pisa is upon us in 2018.
But the recurring theme which struck me from the report was the importance and value placed on equity in education.
This may well be a result of unconscious bias: my organisation, the Education Policy Institute has, at its heart, a moral purpose to tackle inequalities in education, and our recent research on the impact of the government’s proposals in its Green Paper Schools that work for everyone, means that equality and social mobility are often at the forefront of my mind.
Nevertheless, there are some clear messages in Pisa this year about equity and common features of countries that have highly equitable systems, and those that don’t.
Features of an equitable system include:
Intervening before school through early childhood education
Pisa 2015 is clear that investment in early childhood can bring relatively large returns as children progress through school. Students who had attended pre-primary school tended to perform better at the age of 15 than students who had not attended, even after accounting for socio-economic status.
Intervening when students have already fallen behind is often more expensive and less effective.
The OECD’s Education at a Glance report gives us more comparisons about the prevalence and funding of early years provision across the OECD.
This shows that, while take-up of early years provision amongst three- and four-year-olds in the UK is much higher than the OECD average (due largely to the free entitlement and earlier school starting age), the extent to which education and childcare programmes are delivered by a qualified teacher varies.
In high-performing countries such as Canada, Finland and Denmark, these programmes are delivered consistently by a qualified teacher.
Delaying academic selection
Both the OECD secretary-general, Angel Gurría, and its director of education and skills cited evidence from Pisa that the later pupils are put on a differentiated track, the better. This is particularly the case for disadvantaged pupils. Pisa 2015 finds that in countries that sort students into different education programmes at an early age, there is a stronger, negative effect on disadvantaged pupils.
The UK has a relatively low proportion of academically selective schools, but it does make use of "setting" within schools. Pupils in the UK are almost twice as likely to be set by ability into different classes for some subjects, at 75.5 per cent, than the OECD average of 38 per cent.
While some studies cited in Pisa (in Kenya, in particular) find that sorting by ability classes within schools can yield gains in academic attainment for lower performing pupils, the OECD finds that this approach is not associated with greater equity in outcomes.
A clear policy conclusion from Pisa 2015 is that resources should be targeted at schools with high concentrations of low-performing and disadvantaged pupils, in order to achieve greater equity.
The study finds that in countries and economies where more resources are allocated to disadvantaged schools (including in the UK), overall science performance is somewhat higher.
Specific options put forward by the OECD include specialised teachers (those with either specific subject knowledge or training in teaching disadvantaged pupils); instructional materials (such as computers and laboratories); and improving school infrastructure.
While, for the majority of OECD countries, there is no relationship between spending and outcomes in Pisa, the OECD is clear that it is how resources are allocated that is most important.
Nurture resilience amongst disadvantaged pupils
Disadvantaged pupils can outperform their more affluent peers. On average across the OECD, 29 per cent of pupils in the bottom quarter of Pisa’s disadvantage index perform amongst the top quarter of students among all countries. In the UK, 35 per cent of pupils did so, representing a 5 per cent increase since 2006.
Move everyone up – there needn’t be a choice between the top or bottom performers
Since 2006, there has been no significant difference in the percentage of low-performing students in the UK but there has been a reduction in the proportion of high-performing students – of 2.9 per cent and considered statistically significant.
One of the key policy conclusions from Pisa 2015 is that “countries do not have to choose between nurturing excellence in education and reducing underperformance”.
Macao (China) and Portugal have, over the past decade, increased their proportion of top performers in each of reading, maths and science while reducing the proportion of pupils who don’t meet the basic levels of proficiency in those subjects.
Of course, an audience of TES readers probably know all of this already. Did we need it repeated by Pisa?
One of the huge benefits of reports such as this is that education policy debates can be informed by more than what happens in any one country.
We all have a lot to learn from properly researched experience from beyond our borders.
Natalie Perera is executive director and head of research at the Education Policy Institute