England's science education system is not delivering what the country needs. Assessment doesn't measure enough of what matters. The curriculum is too overloaded to teach for understanding. And the research tradition that could fix this has been sidelined for a generation.
ISCA exists to change that. We are an independent body combining England's research tradition in science education with rigorous curriculum design — analysing problems, developing practical solutions, and helping the organisations responsible for science education put them into practice.
Our conclusions are driven by evidence and scholarship alone. We accept no funding from awarding bodies or organisations with a commercial interest in the current system.
ISCA is an independent body specialising in systematic, evidence-based design of science curriculum and assessment. We combine England’s research tradition in science education with rigorous curriculum design to analyse problems, develop practical solutions, and help the organisations responsible for science education put them into practice. Our independence from government and from commercially interested organisations ensures that our conclusions are driven by evidence and scholarship.
Why we exist
England’s science education system is not delivering what the country needs. The 2025 Curriculum and Assessment Review confirmed what the science education community has long understood: that assessment does not measure enough of what matters, that the curriculum is so overloaded that teachers are unable to teach for deep understanding, and that students are not developing sufficient real-world capabilities from science education.
These problems reflect weaknesses in how the curriculum is designed. In the current system, examination specifications have come to define what is taught in classrooms, with the result that what can be efficiently assessed takes priority over what students most need to learn. ISCA calls this qualification-driven design. Its consequences are that excessive content required by the assessments forces teachers to cover the curriculum rather than teach for understanding, rewarding recall over the kind of scientific reasoning that students are likely to need in their lives.
England deserves a more coherent approach to curriculum design. What most drives achievement is a curriculum that is coherent and fully deliverable within available teaching time (Marzano, 2003), not one that is ‘an inch deep and a mile wide’ (Schmidt et al, 1997). ISCA follows an approach we call outcomes-engineered design. Like engineers, we start by defining the desirable outcomes: what students should be able to do with science in the future, such as apply their understanding to unfamiliar phenomena and make informed decisions about real-world issues as well as pursue scientific careers. We then work backwards to define the learning priorities that build towards these outcomes, and only then specify the detailed knowledge and skills. To validate our model, we prototype units to ensure they align with the desired outcomes and manage curriculum constraints (particularly available time) so that the learning for understanding is achievable.
England developed much of the research base for exemplary science education but largely ignores it. Over five decades, researchers at King’s College London, University of York, and UCL Institute of Education have built internationally influential knowledge about how students develop understanding and learn to reason scientifically, and how to develop curricula that develop students understanding of science content as well as their scientific literacy. The Next Generation Science Standards in the United States drew on this research to build a curriculum framework that focuses on the outcomes of understanding and what students can do with what they know, in assessment and in the classroom. England has yet to match that ambition in its own curriculum design.
What ISCA does
ISCA is developing solutions to major curriculum problems with the science education community. We have analysed the problems identified by the 2025 Curriculum and Assessment Review and developed two specific, practical proposals. We presented these at ISCA’s inaugural Expert Advisory Panel meeting in March 2026, attended by thirty key stakeholders including awarding bodies, subject associations, multi-academy trusts, the Royal Society, the Association for Science Education, and leading research institutions. The proposals received strong support.
ISCA proposes to close the gap between what the curriculum aims to develop and what examinations actually assess. Students are expected to develop the ability to reason from evidence, evaluate competing claims, and apply science to real-world contexts, but examinations do not test these capabilities in a meaningful way. ISCA has proposed a new Assessment Objective (AO4) to close this gap: an assessment of scientific reasoning and epistemic practices in authentic contexts. AO4 draws on the PISA scientific literacy framework and has gained support from awarding body professionals who believe that there are no significant barriers to its implementation.
We can remove the biggest obstacle to teaching for understanding: curriculum overload. ISCA’s analysis has quantified what teachers have long known — at GCSE level, the curriculum contains approximately 45% more content than can be taught to the depth that genuine understanding requires. This overload, previously invisible in the design process, is the single greatest barrier to deeper learning. ISCA has developed a principled method for its reduction, drawing on David Perkins' framework for identifying knowledge that is truly worth teaching and Jay McTighe's Understanding by Design approach to building curriculum backwards from desired outcomes. The result is a set of tools called SCULPT, which prioritise and optimise content so that the curriculum is viable. SCULPT has been prototyped and is being made available to the organisations involved in curriculum revision.
Why now
There is only a short window to influence the revision of the national curriculum. The consultation on new programmes of study is underway, and the development of assessment criteria and examination specifications will follow. A revised curriculum will be produced to be taught from 2028. Evidence and recommendations that reach this process in the next twelve months can make a difference to what is decided. Those that arrive later will be lobbying against a settled framework.
ISCA is seizing this opportunity to improve the quality of students’ science education. We are actively participating in the consultation process: contributing formal responses, mobilising the expertise of the science education community, and engaging with DfE and Ofqual to ensure the revision benefits from the best available evidence. Our goal is not simply to publish recommendations but to ensure they are adopted, so that the next generation are better equipped both for STEM careers and to make good decisions about science-related issues in their working and personal lives and to experience a more meaningful science education.
ISCA’s Founding Fellows are scholars whose expertise has shaped its founding purpose and who endorse the work it exists to do.
Jonathan Osborne — Professor Emeritus, Graduate School of Education, Stanford University; Chair of the PISA 2025 Science Expert Group. Jonathan's Stanford webpage
Christine Harrison — Professor of Science Education, King’s College London
David Perkins — Carl H. Pforzheimer, Jr. Professor of Teaching and Learning, Emeritus, Harvard Graduate School of Education; author of Future Wise: Educating Our Children for a Changing World
ISCA develops curriculum and assessment solutions through what we call outcomes-engineered design. Like engineers, we start by defining the outcomes we want — what students should be able to do with science in their lives beyond school. We then work backwards to identify the learning priorities that build towards those outcomes, and only then specify the detailed knowledge and skills. Every proposal we develop is prototyped, tested against the realities of classroom time and teacher capacity, and refined in consultation with practitioners before we put it forward. This is what distinguishes genuine curriculum design from curriculum specification.Designing backwards from life beyond school
A curriculum is a technology — it exists to produce an outcome, and the design process should start from that outcome, not from the inherited structure of a syllabus. We draw on Jay McTighe and Grant Wiggins' Understanding by Design framework, which establishes that coherent curriculum design begins with desired results, then works through the evidence needed to demonstrate those results, and only finally plans the learning experiences that build towards them. ISCA applies this logic at the specification level — asking, for every content item: what future situation does this prepare students for, and how much teaching depth does that preparation actually require?Authentic learning, transfer, and life-worthy content
The most influential reframing of the curriculum question comes from David Perkins, ISCA Founding Fellow and author of Future Wise: Educating Our Children for a Changing World. Perkins argues that curriculum should prioritise what is genuinely life-worthy — knowledge with generative power across the situations students will actually face. This principle is central to our curriculum overload work: when specifications contain far more content than can be taught to depth, the first question is always which content is most life-worthy, and therefore most deserving of the teaching time required for genuine understanding and transfer.Equity through depth, not coverage
Curriculum overload is an equity issue. When teachers are forced into acquaintance-level coverage, students from science-rich home environments can compensate — through books, parental expertise, tutoring, informal learning. Students without that cultural capital cannot. The evidence from cognitive science is consistent: active, schema-building teaching disproportionately benefits disadvantaged students, while surface-level coverage disproportionately harms them. ISCA's proposals for curriculum optimisation and assessment reform are, at their foundation, arguments for equity: every young person is entitled to a science education that teaches science properly, not a reduced version shaped by what can be efficiently examined.Rigorous development of scientific enquiry, integrated with content
Science is not a body of facts to be memorised alongside a separate list of skills to be practised. It is an integrated enterprise — the reasoning, enquiry, and argumentation practices of science are how scientific knowledge is constructed and validated. The research tradition developed at King's College London by Founding Fellow Christine Harrison, alongside Paul Black and Dylan Wiliam, established that assessment is most powerful not as measurement at the end of learning but as an integral part of the learning process itself — formative, diagnostic, responsive to what students actually understand. ISCA's work on a new assessment objective for scientific literacy extends this tradition: assessment design that rewards genuine scientific reasoning will, through washback, change what happens in classrooms.Building on England's research tradition
England developed much of the world's leading science education research — and then largely stopped applying it. ISCA exists to reconnect curriculum design with that evidence base. Our work draws on Rosalind Driver's foundational research on children's ideas in science, the Cognitive Acceleration in Science Education programme at King's, Robin Millar's 21st Century Science, and Jonathan Osborne's work on argumentation and scientific literacy — work that Founding Fellow Osborne has continued at Stanford, including as Chair of the PISA 2025 Science Expert Group and as a contributor to the K–12 Framework underpinning the US Next Generation Science Standards. The evidence base is extensive. What has been missing is an independent body with the mandate to bring it systematically into contact with curriculum revision in England. That is the gap ISCA exists to fill.
ISCA's current work is focused on England's national curriculum revision — the most significant opportunity to improve science education in a generation. We are identifying the obstacles that prevent the ideal science education from being realised, and developing workable, evidence-based solutions that can be implemented within the existing revision timeframe. All four projects are being developed in consultation with our Expert Advisory Panel and with classroom teachers, and formal publications are planned for Spring 2026.1. Revised Purpose and Aims for the National Curriculum
The existing National Curriculum purpose statement does not fully capture the dual mandate of science education: preparing future STEM professionals and equipping every young person with the scientific literacy they need as citizens. Asked by a national body to propose improvements, ISCA has developed a revised four-component purpose statement that places student agency, scientific habits of mind, and real-world capability alongside disciplinary knowledge. The revised aims are designed backwards from these purposes — following the principle that curriculum design must start with what students need to be able to do with science, not with what is convenient to assess.2. A New Assessment Objective for Scientific Literacy (AO4)
Current GCSE assessment cannot measure scientific literacy. The three existing Assessment Objectives reward recall and the application of taught procedures — not the reasoning, source evaluation, and evidence-based decision-making that citizens actually need. ISCA has proposed a new Assessment Objective (AO4), drawing on the PISA 2025 Scientific Literacy Framework, that would assess students' ability to reason with evidence in authentic real-world contexts: evaluating competing claims, distinguishing evidence from opinion, and making informed judgements. The proposal has received support from awarding body professionals and has no significant barriers to implementation. It is the essential complement to curriculum reform — without it, what is assessed will continue to drive what is taught.3. Reducing Curriculum Overload (SCULPT)
The single greatest obstacle to teaching for understanding is that the GCSE specification contains far more content than can be taught to the depth understanding requires. ISCA's analysis of the AQA Combined Science specification found 927 examinable content items requiring an estimated 449–509 lessons to teach properly — against approximately 250–350 lessons available in schools. The result is that over 160,000 students fail to reach a grade 4 every year, despite teachers using evidence-based methods. The problem is not teaching quality. It is specification design.SCULPT is ISCA's curriculum optimisation method, developed to address this directly. Working from David Perkins' framework for identifying knowledge worth teaching and Jay McTighe's Understanding by Design, SCULPT maps every specification item, classifies it by teaching time required, and scores it against what students actually need for STEM progression and for life. It then fills the available lesson budget in priority order — promoting the highest-value content to in-depth teaching and identifying what can be reduced or removed. The result is a specification that is genuinely teachable, with the space to teach for understanding rather than coverage.4. Curriculum Overload Analysis Tool
To support the specification revision process, ISCA has developed a detailed lesson-by-lesson scheme of work for GCSE Combined Science that makes visible, for the first time, exactly how long it takes to teach the full specification to the depth the examinations demand. The tool has been made available to Pearson/Edexcel to evaluate whether the revised draft Programme of Study from DfE has genuinely reduced overload — providing the evidence base needed to make the curriculum manageable rather than perpetuating the failure mode that currently affects half of all students.5. Blueprint: A Five-Year Mastery Curriculum Framework
ISCA is revising Blueprint — a sequenced five-year curriculum framework for secondary science that maps the progression of key concepts across Key Stages 3 and 4. Blueprint provides the coherent conceptual spine that the national curriculum lacks: a structured, research-informed sequence in which big ideas develop progressively across five years rather than being encountered superficially and repeatedly. The revision is being conducted in consultation with school users and is designed to align with the revised national curriculum aims.
ISCA welcomes enquiries from researchers, educators, policymakers, and organisations with an interest in science curriculum and assessment reform.
Tony Sherborne
Founder, ISCA
[email protected]
+44 7757 939007