Spain's Ministry of Education, Vocational Training and Sports identified unusually high student exclusion rates in Catalonia during the 2025 PISA tests, information from official sources. The company contracted by the OECD to oversee the assessments first flagged the irregularity in April 2025, after testing had begun. Technical staff from the National Institute for Educational Evaluation contacted their counterparts at Catalonia's Consell Superior d’Avaluació Educativa to address the issue, as reported by El Mundo and La Vanguardia and confirmed by Europa Press.
At the time, communications about the incident remained at the technical level within both the national and Catalan education administrations. Ministry sources said the issue was not escalated to higher administrative levels because technical teams could not yet determine the scope or potential consequences of the irregularities. The full impact of the excessive exclusion rates became clear only in March 2026, when the OECD released the global PISA results.
The Ministry, led by Milagros Tolón, said officials fully understood how the technical issues had affected Catalonia's PISA results only in March 2026. Sílvia Paneque, the Generalitat's spokesperson and consellera for Territory, Housing and Ecological Transition, said the Catalan government chose not to disclose the error earlier because it lacked concrete evidence. She said it would not have been prudent to inform the public without a minimum level of certainty about what had occurred. Paneque also confirmed that the investigation within the Department of Education and Vocational Training is ongoing.
PISA assesses 15-year-olds in reading, mathematics and science, and is designed to support comparisons between education systems. Its results depend on a representative assessment sample. Excluding eligible students at unusually high rates can undermine comparability. Catalonia's 2025 scores so cannot be compared with those of previous years or other countries, raising questions about data integrity and transparency. The situation echoes previous scrutiny of Catalan authorities over PISA sampling errors, as highlighted in a related report on the political fallout and credibility challenges facing the regional government: Catalonia's earlier PISA sampling controversy.
Spain-wide figures offer a separate national context, not a substitute for comparable Catalonia-specific results. El Español's Observatorio de Educación cited scores of 477 in science, 451 in reading and 457 in mathematics for Spain in PISA 2025. Those national figures do not establish valid scores for Catalonia. The case shows how sampling and exclusion procedures can shape the interpretation of large-scale assessments, and why technical issues that may influence results matter for education policy and public confidence.
