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Research Evidence

UDL is based upon the most widely replicated finding in educational research: learners are highly variable in their response to instruction. In virtually every report of research on instruction or intervention, individual differences are not only evident in the results; they are prominent. However, these individual differences are usually treated as sources of annoying error variance as distractions from the more important “main effects.” UDL, on the other hand, treats these individual differences as an equally important focus of attention.  In fact, when viewed through the UDL framework these findings are fundamental to understanding and designing effective instruction. The research that supports UDL falls into four categories: foundational research of UDL, research on the UDL principles, research on promising practices, and research on implementation of UDL.

To see the specific research evidence related to each Checkpoint, navigate to the individual Checkpoint's page and select the Research link in the sidebar. We've also included a list of links to those Research pages at the end of this page.

Foundational Research on UDL

UDL draws from a variety of research including the fields of neuroscience, the learning sciences, and cognitive psychology. It is deeply rooted in concepts such as the Zone of Proximal Development, scaffolding, mentors, and modeling, as well as the foundational works of Piaget; Vygotsky; Bruner, Ross, and Wood; and Bloom, who espoused similar principles for understanding individual differences and the pedagogies required for addressing them. For example, Vygotsky emphasized one of the key points of UDL curricula—the importance of graduated “scaffolds”. These are important to the novice, but that can be gradually removed as the individual acquires expertise.  Scaffolding with graduated release is a practice that is as old as human culture and is relevant to learning in almost any domain, from learning to walk or ride a bike “unaided” to the long apprenticeships of neurosurgery or aircraft flying.

Research on the Principles of UDL

The research basis for the general principles of UDL is also grounded in modern neuroscience. The three basic principles are built upon the knowledge that our learning brains are composed of three different networks, recognition, strategic, and affective. The Guidelines align these three networks with the three principles (recognition to representation, strategic to action and expression, and affective to engagement). This empirical base in neuroscience provides a solid foundation for understanding how the learning brain intersects with effective instruction. This alignment is further extended and clarified by the guidelines and checkpoints.

Promising Practices Research

Promising lines of research include work identifying the specific practices that are critical to meeting the challenge of individual differences—research that has been amassed over decades and by many different researchers. These studies are labeled as “promising” because they appear to fit within the UDL framework, but they have not been tested in a UDL environment or using the framework. It is important that these practices are studied within a UDL environment for them to be considered effective UDL practices. This is an area in which we greatly encourage contributions from the field.

Implementation Research

Fourth, there is research on specific applications of UDL within learning environments, including conditions necessary for implementation, common barriers, and lessons from the field. This new area of research is in its early stages but will take a more prominent place as full-scale curricular applications and system-wide implementations are developed. It should be noted that this is another area in which we greatly encourage contributions from the research field.

Research Evidence by Checkpoint

Explore the research used to develop each UDL Guidelines Checkpoint.

Do you have UDL-related research you'd like to share? Email us at