The three principles of Universal Design for Learning (UDL) are Engagement, Representation, and Action and Expression. Developed by the nonprofit CAST, these principles provide a framework for designing lessons and learning environments that work for the widest possible range of learners, not just the “average” student. Each principle maps to a different brain network and addresses a different dimension of how people learn: why they’re motivated, what information they take in, and how they show what they know.
The framework was updated to version 3.0 in July 2024, with a stronger emphasis on learner agency, identity, and removing barriers rooted in bias and systemic exclusion. The core three-principle structure, however, remains the foundation.
Engagement: The “Why” of Learning
Engagement addresses motivation. It’s tied to the brain’s affective network, which governs emotion, interest, and the drive to keep going when something gets difficult. The core idea is that no single approach to motivation works for everyone. Some students light up with collaborative projects; others prefer working independently. Some thrive on competition, while others shut down under that kind of pressure.
The Engagement principle breaks into three guidelines:
- Recruiting interest. Give learners choices, make tasks feel relevant to their lives, and minimize unnecessary threats or distractions. A student who can pick their own essay topic, for example, is more likely to care about the work.
- Sustaining effort and persistence. Make goals clear, vary the level of challenge so it stays in a productive zone, build in collaboration, and give feedback that’s oriented toward growth rather than just grades.
- Self-regulation. Help learners develop their own coping strategies, set personal expectations, and reflect on their progress. This is about building the internal skills that keep someone going after the initial spark of interest fades.
In practice, this looks like teachers using reflective journals so students can check in on how they’re feeling about the material, incorporating real-world examples from actual job sites during lectures, or arranging seating in a circle to encourage discussion. One college instructor used service-learning projects and asked students for feedback every class, which gave them both ownership and a voice in the course.
Representation: The “What” of Learning
Representation addresses how information is presented. It’s connected to the brain’s recognition network, which processes patterns, language, and sensory input. Because learners perceive and interpret information differently based on their experiences, abilities, and background knowledge, presenting content in only one format (say, a textbook chapter) inevitably leaves some people behind.
This principle also has three guidelines:
- Perception. Offer ways to customize how information is displayed, and provide alternatives for both auditory and visual content. Captions on a video, adjustable text size, or a diagram alongside a written explanation all fall here.
- Language and symbols. Clarify vocabulary, explain unfamiliar notation, support understanding across languages, and illustrate concepts through multiple media. A math teacher might pair symbolic equations with visual models and verbal walkthroughs.
- Comprehension. Activate background knowledge before diving in, highlight key patterns and big ideas, guide students through how to process and organize information, and help them transfer what they’ve learned to new situations.
One instructor applied this by replacing a single textbook with homemade course materials, weekly videos covering each topic, and curated online resources. Another used videos and simulations alongside traditional readings. The goal isn’t just adding more stuff. It’s presenting the same core content through varied channels so every learner has a genuine entry point.
Action and Expression: The “How” of Learning
Action and Expression covers how students demonstrate what they’ve learned. It’s linked to the brain’s strategic network, which handles planning, organizing, and executing tasks. Just as people take in information differently, they also differ in how they best communicate their understanding. A student who struggles to write a five-paragraph essay might produce a brilliant video explanation of the same concept.
The three guidelines here are:
- Physical action. Vary the methods students can use to respond and navigate materials, and make sure tools and assistive technologies are accessible. This matters for students with motor differences, but it also just acknowledges that people interact with technology and physical materials in varied ways.
- Expression and communication. Let students use multiple media to communicate their learning. The 3.0 update specifically encourages newer mediums like social media or interactive web tools alongside traditional formats. Offer multiple tools for building and composing work, and provide graduated levels of support as students build fluency.
- Executive functions. Help with goal-setting, planning, organizing information, and tracking progress. This can look like posting weekly learning objectives, providing guided notes and graphic organizers, or sharing a reading and lecture schedule at the start of the term so students can manage their own study time.
Teachers put this into practice by offering fill-in-the-blank handouts alongside PowerPoints, aligning written notes to video lectures, or designing class activities where students can demonstrate knowledge through different formats depending on the assignment.
How UDL Differs From Differentiated Instruction
People often confuse UDL with differentiated instruction, but the timing is different. Differentiated instruction is reactive: a teacher observes that certain students are struggling and then adjusts materials or methods in response. UDL is proactive. It builds flexibility into the design from the start, before any student walks through the door. The assumption is that variability is the norm, not the exception, so the learning environment should already accommodate a wide range of needs rather than retrofitting after problems show up.
The 2024 update to the guidelines reinforces this by acknowledging that barriers to learning exist not just at the individual level but at institutional and systemic levels too. It also shifted the language from creating “expert learners” to supporting learner agency, making it clear that both educators and students themselves can apply the principles.
What the Evidence Shows
A meta-analysis of 20 studies found that UDL instruction produced moderate-to-large positive effects on student academic achievement. The benefits show up across age groups and subject areas. Middle school students in a UDL-based curriculum significantly improved their reading comprehension. High school chemistry students, both with and without disabilities, earned higher test scores after UDL strategies were introduced. One school district that implemented UDL-based instruction over several years saw students score above the state average on standardized tests.
In higher education, undergraduate students working with UDL-trained tutors at East Carolina University achieved pass rates between 90 and 100 percent, outperforming students under other tutoring models. College students also reported greater self-confidence and more positive feelings in courses where UDL principles were more fully implemented. Research consistently shows improved engagement in both K-12 and college settings, with students becoming more active in writing, reading, and class participation after UDL frameworks were adopted.
Common Barriers to Implementation
Despite strong evidence, teachers face real obstacles. Large class sizes and low teacher-to-student ratios make it difficult to offer the kind of flexible, responsive instruction UDL calls for. Many teachers, particularly at the secondary level, report feeling constrained by rigid curricula and standardized testing requirements. When students need to pass specific certification exams to graduate, teachers feel pressure to “teach to the test,” which leaves little room for the open-ended, multi-modal approach UDL encourages.
Some teachers also note that they’re required to follow specific programs or materials, making inclusive pedagogy hard to adopt even when they believe in it. Financial burdens and insufficient staffing compound the problem. A scoping review of teacher beliefs found that while most educators considered UDL effective for inclusive education, they found it extremely challenging to reconcile with the realities of standardized accountability systems.