In a recent podcast episode about international assessments, EDT explored how tests like the Programme for International Student Assessment (PISA) benefit global education. These tests reveal how well students across the world perform in critical subjects such as reading, mathematics and science. For countries aiming to boost their PISA scores, particularly those consistently underperforming, one promising path is curriculum reform that applies the principles of cognitive load theory (CLT), pioneered by John Sweller.
In this article, we examine how CLT can inform curriculum design and classroom practices, offering concrete strategies to improve student outcomes. Focusing on a CLT-friendly approach to curriculum reform can free up the time needed to teach the sort of lessons that the higher-level PISA questions demand. This will enable children to develop their linguistic comprehension sufficiently enough for them to evaluate, synthesise and apply their knowledge and understanding.
Understanding cognitive load theory
Cognitive load refers to the mental effort necessary to complete a task and to effectively transfer learning from ‘working memory’ to ‘long-term memory’. You know things are in long-term memory when they can be recalled after the learning has initially taken place. To get things into long-term memory you have to ‘work’ them, in working memory, to make them stick (this transfers them to long-term memory). One example is what happens when you get a new phone and the effort it takes to remember it. With effort the number will enter your long-term memory, but not the first time you saw it, when it is likely to go straight in and out of working memory. Working memory lasts for only a short period (while you consciously think about something). It is also quite limited and can easily become overloaded, resulting in information loss – like when you put too much water in a glass. Applying CLT to education is all about making sure the metaphorical ‘glass’ is full but not overflowing when new learning is taking place.
CLT identifies three types of cognitive load that influence learning:
- Intrinsic cognitive load: Intrinsic load is the mental effort required to process the complexity of the material itself. The difficulty of a topic, such as advanced mathematics or a complex scientific concept, directly impacts this type of load. There is evidence that increased intrinsic load affects us physically, although how to interpret this evidence is tricky since high levels of performance are also associated with moderately increased arousal. What is clear is that working memory can easily be overwhelmed if learning is not broken down into appropriate chunks and learned well, before more complex content can be associated with it.
- Extraneous cognitive load: Extraneous load stems from distractions or poorly designed materials that tax students’ cognitive resources unnecessarily. It does not contribute to learning and should be minimised. Extraneous cognitive load is also influenced by the way that teachers teach and engage with their classes.
- Germane cognitive load: Germane load is the productive mental effort used to process, organise and integrate new information into existing knowledge. It is essential for deep learning and long-term retention. It can be seen as the quality of internal resources the student themselves dedicates to the learning process. Helping students to be metacognitive with their learning (having a clear goal, self-monitoring, and the ability to select different strategies and self-evaluate while learning) are key tools for enhancing this. Indeed, , perhaps for this reason, remain among the highest performing areas in repeated randomised controlled trials with an average of seven months’ gain in 12, found across 246 studies.
Based on the different types of cognitive load above and their effects, we recommend five ways to reform school curricula for better student outcomes:
1. Rethinking curriculum design: managing intrinsic cognitive load
Curriculum reform should focus on aligning the difficulty of the material with students’ cognitive abilities, ensuring they are appropriately challenged without being overwhelmed.
- Build complexity gradually: Design curricula that introduce concepts with a logical progression, beginning with foundational ideas and gradually advancing to more complex topics. This approach allows students to develop confidence in their learning before tackling more difficult subjects.
- Match content to cognitive development: Ensure the curriculum is tailored to the students’ developmental stages. A common issue in low-performing countries is a mismatch between what students are capable of understanding and what they are being taught.
- Consider scaffolding in curriculum design: Introduce new information in manageable amounts, providing support until students are ready to handle the material independently. Scaffolding helps manage intrinsic load, ensuring students are not overwhelmed by too many complex concepts all at once.
2. Reduce extraneous cognitive load through clear instructional design
Reducing extraneous load involves simplifying the presentation of information and removing distractions, allowing students to focus on the core content.
- Streamline materials: Instructional materials should be clear, concise and free from unnecessary information. In many underperforming school systems, textbooks and resources are cluttered with irrelevant details that distract from the main learning objectives. Alternatively, teachers may not be confident enough to select appropriately from textbooks and instead teach every exercise on every page.
- Provide teacher support: Equip teachers with guides that outline strategies for reducing extraneous cognitive load in the classroom. This might include tips for simplifying explanations, using straightforward language, and eliminating distractions.
- Use dual coding and chunking: Encourage teaching methods that combine visual and verbal information (dual coding) and break content into smaller, manageable units (chunking). Teacher guides should provide specific strategies for implementing these methods in the classroom.
- Design for accessibility: Ensure that materials are accessible to all students, including those with learning difficulties. Consistent, easy-to-navigate resources help reduce extraneous load by making the material easier to understand and engage with.
3. Foster germane cognitive load to deepen learning
Germane load is the mental effort devoted to building and refining cognitive frameworks, or schemas, which help students make sense of new information and retain it, long term. A schema is a mental blueprint or pattern that allows us to understand new experiences based on what we already know.
For example, you probably have a schema for what happens in a restaurant.
- You know that when you walk in, you’ll be greeted and seated.
- Then, you’ll look at a menu, order food, and eventually pay at the end.
This mental framework helps you navigate the situation without needing to think about each step. Schemas simplify how we process information, but they can also lead to misunderstandings if something doesn't fit our expectations.
For example, if you go to a new type of restaurant, such as a buffet, your schema may not fit the scenario, and you may at first be unsure what to do. For example, do you wait for someone to bring you food, or do you serve yourself? As you learn the new rules, your schema adjusts.
In the biology curriculum, students need to develop a schema around the concept of cells. Initially, students might learn that a cell is the basic building block of life. Their schema for cells could be something simple, like “cells are tiny units that make up plants and animals.” This helps them understand that all living organisms are made of cells.
Later, when they are introduced to cellular respiration, they can build on this schema. The teacher explains that cells need energy to function, and they get this energy through a process called cellular respiration, where they break down glucose to produce energy. Because students already have a schema for cells being the fundamental units of life, they can attach the new idea (cells needing energy and performing respiration) to this framework.
This expanded schema helps them understand more complex biological processes such as metabolism, photosynthesis and how the body’s energy system works. Their initial knowledge about cells acts as a foundation for deeper biological understanding.
Schemas are the psychological product of the web of interconnectivity between neural networks that we create when we learn information and associate it with already existing knowledge. We grow these networks as our knowledge and understanding develops. Importantly, once you have a well-learned schema in place, it effectively counts as one chunk of information in your working memory, freeing up space for more ideas and associations. Even highly complex tasks like driving a car can become automatic in this way, allowing other processing to take place – for example, talking to your friend as you drive.
Promoting germane load is essential for helping students move beyond memorisation to real, conceptual understanding.
- Encourage ‘effortful’ thinking: when your learners engage in ’effortful’ thinking about new information, you are helping their brain to integrate it into a broader web of knowledge, which makes learning deeper and more durable. Incorporate methods such as thinking through questions, dialogue, and problem-solving activities. Engage students actively and encourage them to form deeper connections with the material.
- Support schema building: Structure curricula to support schema development by introducing new information in a way that builds on existing knowledge. This makes it easier for students to integrate new concepts and apply them in different contexts.
In turn, the structure of the curriculum needs to ensure that it is built to promote opportunities for schema building whilst managing intrinsic load.
4. Invest in teacher training for cognitive load management
While curriculum design plays a key role in managing intrinsic cognitive load, it is teachers who are responsible for managing extraneous and germane loads in the classroom.
- Train teachers in CLT: teacher professional development should include training on how to manage different types of cognitive load in the classroom. Teachers need to understand how to simplify complex topics, reduce distractions, and encourage deeper learning through schema-building activities.
- Provide practical strategies: offer teachers evidence-based strategies for managing cognitive load, such as scaffolding lessons, using visual aids, and designing clear, focused assessments.
- Ongoing professional development: ensure continuous training opportunities for teachers so they can refine their cognitive load management techniques and stay up to date with best practices in instructional design.
5. Support teachers with clear and practical guides
Even with training, teachers need ongoing support to apply CLT principles in their day-to-day instruction. Comprehensive teacher guides are essential for bridging the gap between theory and practice.
- Offer clear instructional strategies: Teacher guides should provide step-by-step strategies for reducing extraneous load and increasing germane load. This could include advice on how to present complex information visually, or how to break down lessons into manageable steps.
- Classroom management advice: Effective classroom management reduces distractions and helps students stay focused, thus lowering extraneous cognitive load. Guides should provide practical advice on maintaining a distraction-free learning environment.
- Promote schema-building activities: Include specific activities in teacher guides that encourage schema development, such as collaborative projects, problem solving, and real-world applications of theoretical knowledge.
Taking a CLT-informed approach to curriculum reform and classroom practices can free up teachers’ time to teach and enable children to develop their capacity to learn. This could have a positive impact on education outcomes generally, and PISA scores in particular. We recommend rethinking curriculum design to better manage students’ intrinsic cognitive load – reducing their extraneous cognitive load and fostering their germane load, while supporting teachers with clear CLT strategies and training.
