Overall, the headline findings from Programme for International Student Assessment (Pisa) 2018 will be a relief for those who have overseen education in England for the past eight years - although many will argue that the significant reforms introduced since 2010 should have resulted in greater improvements in these international assessments.

England now outperforms the average across Organisation for Economic Cooperation and Development (OECD) countries in all three subjects that are assessed - reading, science and maths.

Pisa results: Maths

England did particularly well in maths, improving significantly for the first time. Importantly, this was driven by better performance among lower achievers, and among boys. England’s score is now in line with that of Finland, which has been considered one of the high performers in Pisa in the past.

Science

England continues to perform well in science, and above the OECD average, with no significant change since 2015. However, the gap between high and low achievers here continues to be larger than the OECD average.

Reading

In reading, the major area assessed in Pisa 2018, England maintained the higher level of performance it achieved in 2015, and continued to score significantly higher than the OECD average. The number of countries performing significantly better than England fell (from 12 to nine), and boys improved significantly, narrowing the gender gap.

However, Pisa alone cannot tell us why countries have performed in a particular way, or the extent to which this reflects government reforms. It is a snapshot in time, providing a check on how countries are performing relative to each other, and highlighting those which are performing well or improving, from which we might be able to learn. 

Alongside government reforms such as the introduction of the new national curriculum in 2014 and subject-specific initiatives such as maths hubs, many other factors will have influenced the performance of this cohort of pupils - in particular, their prior attainment, which is not taken into account in these headline figures.

And there are other reasons for politicians to pause before celebrating success.

The problem of student wellbeing

While more than 90 per cent of young people in England report being happy some or all of the time (in line with the OECD average), students here also report being less satisfied with their lives, and experience negative emotions, such as being worried or sad, more often than across the OECD. 

It is difficult to draw conclusions about wellbeing across countries - because of the different ways in which young people might choose to answer these questions. But these findings echo the growing concerns about young people’s wellbeing and mental health in this country. This is an important area for the government - as a whole - to monitor and address across the UK. There are wider factors beyond the school gates that affect wellbeing and this is an issue that cannot be tackled by schools alone.

School workforce

One big surprise in the data is the fall in the extent to which headteachers in England consider a lack of teachers to be affecting teaching at their school. In Pisa 2015, this was 45 per cent, substantially higher than the OECD average of 29 per cent. In 2018, the proportion of heads reporting a lack of teaching staff as a challenge fell to 27 per cent, in line with the average across OECD countries.

We know that secondary schools are facing a significant teacher supply challenge as pupil numbers grow and with missed teacher recruitment targets for seven years in a row. This finding warrants further investigation, and consideration alongside the latest data from the Teaching and Learning International Survey (Talis).

Reading enjoyment

We find that young people in England are more confident in reading. However, they are less engaged readers than those in other OECD countries. Over half only read if they have to, rather than for enjoyment, and 30 per cent say reading is a waste of time (an increase since 2009, when reading was last the major domain). Across the OECD as a whole, over a third of young people say they rarely or never read books.

Whilst this doesn’t appear to have affected England’s positive scores in reading (on average), it is of concern, given the importance of reading - for future learning, stimulating creativity and imagination (sought after by employers), and for enjoyment. There are similar challenges across the nations of the UK.

There will be different views on whether these findings offer support for government reforms since 2010 or not, and further analysis of the data is needed to fully explore what is really driving the findings. But it is clear that there are still challenges to tackle and there is scope to improve. Alongside the concerning findings on wellbeing, there is still a gap (of 39 points - over a year of learning) between those eligible for free school meals (FSM) and others, similar to that observed in reading in 2015. This is in spite of the introduction of the pupil premium in 2011. Addressing this issue continues to be a challenge for England.

Carole Willis is chief executive at the National Foundation for Educational Research

NFER was contracted to carry out Pisa 2018 in England on behalf of the Department for Education. However, this article has been produced solely by NFER and does not necessarily reflect the views of the Department for Education