Catalan president defends education minister ahead of parliament appearance over PISA 2025 sample error that excluded 23% of students

The sample that broke comparability

Catalonia’s 2025 PISA results will not be comparable with other regions or with its own past editions after a technical error left 23.2% of the selected students out of the exam. The OECD recommends a maximum exclusion rate of 5%, but 592 of the 2,545 pupils in the Catalan sample were removed because they presented special educational needs. The Department of Education acknowledged in late July that the incident “compromises the comparability of Catalonia’s results with those of previous editions and with those of other territories”, although the raw scores will still be published.

Political fallout and parliamentary scrutiny

The controversy will reach the Catalan Parliament on Monday, when education councillor Esther Niubó appears before a committee. President Salvador Illa, on an official trip to Da Nang, Vietnam, told reporters he wants to “highlight that it has been a technical issue to do with the exempted students and does not go beyond any other consideration of this kind” and said Niubó will give all the explanations. He then closed ranks with the councillor amid opposition calls for her resignation:

To be clear, the councillor has all my support.

Junts had previously criticised Illa’s silence. Party spokesperson Mònica Salas said the government “is overwhelmed and the president absent”, demanding political accountability for the failure.

Why the sample error stings

Catalonia’s last PISA scores were already described as “catastrophic”, with drops of 30 to 40 points in reading, mathematics and science compared with prior waves. Losing the ability to benchmark the 2025 results against those of other Spanish communities and countries deepens the political cost. Tensions between the Department and school principals were already high after months of strikes and union threats to continue mobilisations at the start of the new school year.

What went wrong and when

The sample design left teachers, who decide which pupils sit the exam, without clear guidelines from the Department on the exclusion criteria. Education officials learnt of the situation in March but did not make it public until late July. The government has now opened internal information proceedings to clarify what happened and has created a coordination commission for tests and evaluation studies to prevent a repeat.