The increased capabilities offered by digital technologies offer new opportunities to evaluate students' deeper knowledge and skills and on constructs that are difficult to measure using traditional methods. Such assessments can also incorporate tools and interfaces that improve accessibility for diverse students, as well as inadvertently introduce new accessibility barriers. Designing these technology-enhanced tasks according to universal design principles is one way to address these accessibility concerns, but requires a grounded understanding of students' diverse abilities and the ways they interact with the tasks. A thorough consideration of the factors that impact construct validity, with an emphasis on identifying and eliminating sources of construct-irrelevant variance, is essential to this process. This report proposes a framework based on the principles of Universal Design for Learning (UDL) for defining task design guidelines consistent with the goals of universal design and thus accessible to a wide range of students, including those with disabilities and who are English learners.