Since 1995 over 60 countries have been involved, collecting and interpreting important data on the mathematics and science performance, attitudes and learning experiences of 9-10-year-olds and 14-15-year-olds. Wales will be taking part in TIMSS for the first time in 2027, just at the 9-10 year old level. This data opens avenues for evaluation and development of national education provision. The approach used means that countries that participate over successive cycles can track changes in performance, attitudes and experiences over time, as well as compare their own data with that of suitable comparator countries.

All countries explore these outcomes across different demographic groups (for example, by sex, across indicators of poverty, and in bilingual countries such as Wales, by language also). This will also be a valuable opportunity to better understand the experiences of children learning within Curriculum for Wales by gathering important evidence on its progress. The national research teams behind TIMSS work carefully to communicate the curriculum and teaching and learning approaches in each country and to identify how they are matched to the TIMSS assessment questions. This will enable parents, schools and Welsh Government policy-makers to gain real insight into what children in Wales are learning in mathematics and science by Year 5. Analysis will also support the Welsh Government in understanding the extent to which that is supporting their vision for children and young people.