'The biggest lesson from Pisa's results is that something must be done about teacher recruitment and retention'
Unless the English education system puts a greater focus on teachers, we can't expect to take the next big leap forward, says a headteachers' leader.
What does today's Programme for International Student Assessment (Pisa) report tell us? As far as England is concerned, not much has changed since 2006. The average scores in science, maths and reading have remained stable.
Our 15-year-olds continue to perform above the international average in science, remain average in maths and are above average in reading.
Given that there has been a tidal wave of education reform in the intervening decade, people are entitled to ask why this has not propelled us up the rankings.
We have seen ever more stringent accountability measures, the wholesale restructuring of the school system, and significant changes to the curriculum and qualifications.
So what does Pisa 2015 tell us about the success or otherwise of these changes? Has it been worth all the blood, sweat and tears? And are we heading in the right direction?
It has, at least, not had a negative impact. That is not an entirely flippant observation. The huge turbulence caused by these waves of education reforms could easily have had a negative impact, as schools struggled to cope with constant change and disruption.