Experts divided on results of Wales' international school tests

Wales' results in international maths, reading and science tests have been called "catastrophic" by some, while others have warned against using "just one narrow measure" as a verdict on education standards.

Tuesday's publication of the latest Programme for International Student Assessment (Pisa) study showed Welsh teenagers' scores had fallen further behind 15-year-olds in other UK nations.

Education Minister Anna Brychan said Wales' scores were "not where we want them to be" and a new literacy and numeracy plan would be unveiled next week.

What else does the data tell us about how the nation's education system is performing?

Literacy consultant Finola Wilson believed the percentage of children scoring below baseline levels was a serious problem.

In reading, 31% of the Welsh pupils who took the test scored below what is considered to be the required level to participate effectively in society - a significantly larger proportion than in other UK nations.

"That's why I believe that these results are really catastrophic for Wales," she said.

"Young people are competing for jobs and university places," she added, "and they are going to struggle if there are so many in Wales who can't participate through their reading."

In maths, 36% were below baseline levels. In Wales, as in the rest of the UK, the most advantaged pupils outperformed poorer students.

Brychan said there were "indications that the Welsh education system compares favourably in the way it supports disadvantaged learners".

However, Wilson said it had been "quite shocking" that disadvantaged children in England had performed above the Welsh average in reading.

The data showed the least advantaged in England had performed at about the average in Wales for science and maths - and significantly above the average in reading.

Scotland's most disadvantaged had also performed above the Welsh average in reading.

Overall, Pisa had shown a general decline in performance, and results in some countries had fallen dramatically.

Mary Richardson, one of the authors of the report on Pisa 2025 for the Welsh government, said the tests were a "useful indicator of one kind, but they are not an overarching description of how well the system is doing".

Her analysis of Wales' results were not as damning as some, and she said it had not seen the rate of decline experienced by other countries.

"Hong Kong is a good example of this - you did see dramatic declines in performance in mathematics and reading," she said.

"This isn't just a Wales or Western Europe problem, it's a global issue - even those higher achieving countries saw some elements of decline.

"There are things at play here beyond education itself, it may be societal, it may be technological, we're not sure, and we need to do the research into this next."

Although Wales' results were the lowest of the UK nations, they were similar to France and Hungary in all subjects.

Wales performed below Sweden and Slovenia, and above Malta in science; below Italy and Turkey, and above the Netherlands in reading; and below Belgium and New Zealand, and above Vietnam in maths.

Schools could choose to do the test in Welsh or English, and in 2025 pupils at 2,904 schools did it in English, 456 in Welsh, and 30 in a mix of both.

Prof John Jerrim, an academic at University College London, said over several rounds of Pisa, tests taken in Welsh had scored much lower.

But, this time, they had been about 70 marks lower in Welsh, with scores about 400 on average, he said.

The overall average was 459.

"More than likely... it's a technical issue in and around the testing - so there's something strange going on, quite possibly, in the translation," he said.

"I don't think we've quite got to the bottom of exactly what this is."

But he thinks it is having an impact on the overall scores.

"That's partly attributable to why Wales is doing so poorly, particularly in reading, and particularly compared to the other parts of the UK.

"I don't think it can explain the entire difference.

"It's artificially dragging the scores for Wales downwards, but it's not the only thing at play here."

Brychan said the government would be looking at the issue.

"I know that in the past there have been issues around translation of terms, for example, but a lot of work has happened to iron some of those out.

"If there are issues that we still need to deal with, we need to unpack those," she said.

The Welsh government said it was working closely with the Organisation for Economic Co-operation and Development (OECD), which runs the tests, "to review the translation and linguistic adaptation arrangements for Pisa".

"Welsh language and subject experts will continue to play an important role in validating assessment materials, supporting linguistic accuracy, cultural appropriateness and a fair basis for learners in Wales to demonstrate their knowledge and skills in future Pisa cycles," it said.

There had not been a significant gender gap in science, while girls in Wales significantly had outperformed boys in reading scores in 2025 and the gap had widened over the past decade.

In 2025, boys had continued to outperform girls in maths.

Teachers' unions warned against seeing the Pisa results as the only measure of Welsh education.

Nicola Fitzpatrick, secretary for the National Education Union Cymru, said the results "represent just one narrow measure and that they should not be seen or used as a definitive benchmark for education quality across Wales".

She said there was a crisis of underfunding, while Ioan Rhys Davies from the UCAC teachers union called for "robust financial investment in our schools, therefore leading ultimately to an improvement in standards".

In 2010, the Labour education minister at the time, Leighton Andrews, called that year's Pisa results a "wake-up call".

He believed "the new curriculum has been a major distraction from the school standards agenda over the last decade".

But he thought the current education minister was "right to focus on literacy and numeracy".