Two structural problems in science education have never been fixed: assessment that cannot measure what the curriculum claims to develop, and content overload that makes genuine understanding impossible. The current curriculum revision is a rare opportunity to act on both.
We are asking science teachers and educators to add their names to an open letter calling on the Secretary of State for Education to consider two specific proposals.
England's National Curriculum aims for students to evaluate evidence, weigh trade-offs, and make informed decisions on issues like climate and health. But if assessment doesn't measure these capabilities, teachers cannot justify teaching them, and the aims remain words on paper. Scientific reasoning in authentic contexts — the kind PISA already assesses internationally, under Jonathan Osborne's leadership — sits entirely outside the scope of AOs 1–3.
We call on DfE to introduce a new Assessment Objective 4, weighted at around 10%, assessing scientific reasoning in authentic real-world contexts. Geography and History GCSEs already accommodate exactly this kind of reasoning through their own AO4s. England's science curriculum should too.
42.5% of Higher Tier students failed GCSE Combined Science in 2024. Not because they can't learn science. Because the specification asks for 45% more teaching time than schools have.
Teachers are forced to race through content rather than build understanding. The burden falls hardest on disadvantaged students, who experience science as disconnected facts and disengage before discovering that science is for them.
We call on DfE to enable a principled curriculum optimisation — using subject associations' own Big Ideas frameworks to score every content item, and a computational method to generate auditable decisions about what to teach in depth, what to retain at acquaintance level, and what to remove. David Perkins' framework for identifying content worth teaching in a complex world, and Jay McTighe's Understanding by Design, provide the theoretical foundation. The result: a viable curriculum that fits within 350 available lessons and creates genuine space for depth, climate education, and real-world capability.
▶ Dylan Wiliam (1 min 46): "Stop teaching good things to give time to teach the even better things more effectively."
On 26 March 2026, a group of researchers, policy specialists and practitioners are meeting at Pearson Education, London — and online — to pressure-test these proposals with the current curriculum revision in mind. Speakers include:
Dylan Wiliam — Professor Emeritus, UCL Institute of Education. In recorded conversation, Dylan addresses why curriculum overload has persisted despite decades of reform, and what it would take for this revision to be different.
Jonathan Osborne — Professor Emeritus, Stanford University, and Chair of the PISA 2025 Science Expert Group. Jonathan presents the case for AO4, drawing on the international framework for scientific literacy he helped define.
Shauna O'Brien — Head of Science, UK Schools Product Development, Pearson Education. Shauna examines what AO4 would mean in practice for specification and assessment design.
David Perkins — Carl H. Pforzheimer Jr. Professor of Teaching and Learning, Emeritus, Harvard Graduate School of Education, and author of Future Wise. David provides the framework for deciding what content is worth teaching in a complex world.
Jay McTighe — Co-creator of Understanding by Design, used by thousands of schools worldwide. Jay brings the backwards-design structure: start with what students must ultimately be able to do, then build back to the curriculum that makes it possible.
100+ science teachers, educators and researchers support this letter — including 30 specialists attending the expert meeting on 26 March.
Signatories include: Dom Shibli, Head of ITE, University of Hertfordshire · Gavin Butler, Deputy Headteacher, Sir John Leman High School · Amanda Clegg, School Improvement Consultant, AKC Educational Consultancy · Kirsty Hughes, Director of Science, Paignton Academy · Zoe Ellis, Head of Science, West Kirby School and College · Rozie Harrison, Deputy Director of Science, Sir John Leman High School · Kerry Tomlinson, Chemistry Teacher, Canon Slade · Samantha Paterson, Science Teacher, John F Kennedy School · Nicole Taylor, School Improvement Lead, Roseland MAT · Harvey Eperon, Head of Biology, Langley Park ... and many others.
Add your name below — and tell us why the proposals matter.
"GCSE assessment often forces me to prioritise exam technique over real scientific reasoning. Students learned how to write the 'right' exam answer rather than how to genuinely analyse evidence like scientists do."
— Zoe Ellis, Head of Science, West Kirby School and College
"Real-world skills are impossible to teach — there is never enough time to adequately analyse or process practical results. It is a constant churn through content." And: "We are always making decisions to cull content — there is just too much — and some topics barely even feel like Chemistry."
— Stephen Simkin, Second in Chemistry, King's Academy Binfield
"The rush of getting through things has meant that I have not been able to spend time addressing misinformation around vaccinations."
— Samantha Paterson, Science Teacher, John F Kennedy School
"Only one? The sheer quantity of work to cover in the curriculum is outrageous."
— Daniel Clarke, Science Teacher, North Bridge House
Organised by Mastery Science and The Open University, in collaboration with Pearson Education. Contact: [email protected]