According to the Institute of Education Sciences  , those with a learning disability (LD) and/or attention deficit hyperactivity disorder (ADHD) collectively represent almost half of all students with disabilities (SDs) attending two- and four-year postsecondary institutions. Their attendance rate (60.9%) is lower than those of typically developing students (62.1%)  , as is their college completion rate (37.5% and 51.2%, respectively) . While many reasons have been offered for this discrepancy, these figures reflect the difficulty that SDs experience in adjusting to postsecondary school  , as they are often not ready for academic college programs  , showing difficulties in the areas of organization, attention, cognition, and information processing .
Students with disabilities at the postsecondary level need programs that adapt to their special needs   , but at the same time allow the curriculum to be used with all students. To that end, specific strategies have been offered to help students of various educational, cultural, and linguistic backgrounds to succeed in college . However, while considerable research has been conducted on curriculum and/or strategies for increasing learning outcomes for students without disabilities at the postsecondary level (e.g., ), few investigations have addressed such solutions for SDs .
One of the more promising strategies in this regard is use of the principles of universal design for learning (UDL), which is intended to help all learners succeed . Universal design for learning is based on universal design (UD), originally describing the way buildings and environments can be designed to maximize their inherent accessibility to a diverse body of people . Seven principles serve as the foundation for UD to maximize the accessibility and usability of aggregate surroundings  : equitable use, flexibility in use, simple and intuitive use, perceptible information, tolerance for error, low physical effort, and size and space for approach and use.
Regarding UDL, its principles include multiple representations, multiple expressions, and engagement . Multiple representations refer to the provision of choices to modify the visual and auditory information and interface, including the means of communication, letters, or figures. Multiple expressions refer to the provision of multiple ways to express students’ knowledge and skill acquisition. Finally, engagement refers to the provision of choices to enhance motivation for learning and options for internal and external factors, such as self-regulation and self-discipline, to maintain motivation. Altogether, these principles offer an outline for instructional actions, such as goals, methods, materials, and assessments, for the purpose of developing built-in, flexible approaches that are available to each student . A number of frameworks for enhancing accessibility and equity for SDs exist, to include UDL, universal design for instruction (UDI), and universal instructional design (UID)  . All are similar in approach, with the terms often used interchangeably (e.g.,  ).
Regrettably, empirical examination of UDL implementation and strategies in postsecondary education is lacking, even though numerous studies have been published on the principles, history, and philosophy of UDL . In the context of special education, the reason for this void might be the fact that the Individuals With Disabilities Education Act  mandates free appropriate public education (FAPE) for SDs in K-12, but FAPE is not mandated at the postsecondary level . Necessary accommodations (e.g., curriculum and textbooks) for SDs in K-12 are directed and included in their individualized educational programs; however, legal services are not required for SDs at the postsecondary level, and state governments do not offer proactive direction. Compounding matters, while special education teachers in K-12 are specifically trained to teach this population with a focus on pedagogy   , instructors at the postsecondary level are typically not trained to work with and address the special needs of SDs.
1.1. Purpose and Research Questions
This systematic review explored methods of UDL implementation for postsecondary students with and without disabilities and the degree to which these methods are effective. The aim was framed by the following questions:
Question 1: What are the delivery modes of the courses utilized or UDL implementation?
Delivery modes were explored as one of the built-in mechanisms of UDL practices because UDL is believed to enhance accessibility to curriculum. At the same time, delivery mode has not been explored as a built-in mechanism in existing research.
Question 2: What are the independent and dependent variables?
All studies were empirically based. Each study had independent and dependent variables. The outcomes of each study resulted from the implementation of the independent variable as interventions or experiments. The dependent variable was investigated from the intervention. Thus, the independent and dependent variables were explored.
Question 3: What are the strategies used, and are they effective?
Given the fact all studies were empirically based, the UDL implementation was used for educational settings. To enhance the efficacy of the independent variables, specific strategies were used in the intervention as the element of UDL. Thus, specific strategies used in the UDL implementation for post-secondary educational settings were explored.
The authors systematically and independently searched three databases: Educational Resources Information Center (ERIC), PsycINFO, and Professional Developmental Center. The searches were limited to peer-reviewed, empirically based studies published in English. The terms universal design for learning, universal design for instruction, and postsecondary education were used as the descriptors. A total of 102 studies were identified that met these search criteria.
2.1. Inclusion Criteria
Each of the 102 studies were independently reviewed for inclusion based on the following criteria: the study had to 1) be empirically based; 2) contain the terms universal design and/or UD, universal design for learning and/or UDL, and/or universal design for instruction and/or UDI in the title or abstract; 3) have identified the participants; and 4) either implement UDL practices or conduct a survey or interview on UDL intended to enhance knowledge about or implementation of UDL practices for diverse, postsecondary-level learning populations.
Of the 102 studies examined, the authors independently identified 16 studies, among which 14 were common among the authors. This amounted to an 88% agreement rate on the inclusion criteria use. Some of the 16 studies had been published in the same journals. That is, some of the journals had published two or more of the 16 studies. Upon reviewing these journals, the authors identified two additional studies that met the aforementioned inclusion criteria. The result, therefore, was a total of 18 studies.
The authors together scrutinized the 18 studies in a second review using the same inclusion criteria. This ended in an agreed-upon removal of three studies. Two additional studies were also reviewed because they had been cited by two or more of the remaining studies and met the inclusion criteria. In sum, the removal of the three studies coupled with the addition of the two studies resulted in a final count of 17 studies for review.
2.2. Data Extraction
Information was next extracted from the 17 studies in three passes. In the first pass, the studies were summarized for 1) participant information, 2) courses and delivery mode, 3) independent and dependent variables, 4) implementation outcomes, and 5) elements of UDL in the implementation. In the second pass, implementations were further fleshed out, summarizing 6) research methods, 7) implementation strategies, 8) technology implementation, and 9) class activities related to the UDL principles. Finally, in the last pass, the effectiveness of the implementations was assessed. That is, the findings were classified as effective, for studies in which the course or instruction for the workshop was designed, implemented, and had higher course evaluation and significant improvement; or blended, if the outcome was not better than or the same as that of the control group, but still showed improvement in the learning assessment.
2.3. Inter-Coder Agreement
Inter-coder agreement was assessed on the extracted information using a checklist developed by the authors. The checklist comprised the following six questions: Is the statement about the―1) participant information, 2) courses and delivery mode, 3) independent and dependent variables, 4) implementation outcomes, 5) elements of UDL in the implementation, and 6) assessment of the effectiveness of the implementation―clear and precise?
A total of 102 items (17 studies by 6 checklist items) were assessed. The authors reached an initial agreement rate of 95% on 97 of the 102 items regarding their belief that the extracted information from the 17 studies was clear and precise, deliberating on the remaining four items until reaching consensus.
Table 1 depicts the information extracted from the 17 studies, published in 12 journals. That is, 1) participant information, 2) courses and delivery mode, 3) independent and dependent variables, 4) findings, 5) effectiveness of implementation, and 6) elements of UDL in the implementation.
As shown in the table, six studies used mixed methods (see  - ), seven used quantitative methods (see  - ), and four used qualitative methods (see    ). Two studies conducted experimental and control group comparisons (see  ), while three used pre- and posttests (see   ). (Table 1 does not call out the implementation strategies in a separate column; rather, the strategies are nested within the other table columns as part of implementation, delivery modes, or elements of UDL.)
The 17 studies incorporated interviews, surveys, interventions, or control/experimental group experiments. Across the studies, a total of 4879 participants were found, including 3185 (65%) students at postsecondary institutions, 1605 (32.9%) faculty members, 16 (0.33%) disability service providers, 35 (0.72%) administrators, 21 (0.43%) teachers, 5 (0.1%) instructors or teaching assistants, and 12 (0.25%) individuals not specified (as teachers or faculty). Of the 3185 students, 57 (1.79%) were preservice teachers, 136 students (4.3%) had disabilities, including LD, ADHD, cognitive disability (CD), physical disability (PD), and mobility-related disability (MRD). Six students (4.4% of the 136 participants with disabilities) were reported to have a dual diagnosis. No further information
Table 1. Analysis of Studies.
was offered regarding the number of participants in each of these disability categories.
3.2. Courses and Delivery Mode
Ten studies were conducted in the students’ classrooms (see          ). One study was conducted outside of the classroom as peer-mentoring team teaching, but the outcomes were measured using grade-point average (GPA) taken from science, technology, engineering, and math (STEM) courses for which tutoring was provided (see ). Two studies used a blended approach (see  ). Three studies were conducted in special education courses: two used a blended delivery (see  ), and one was delivered as face-to-face (F2F) (see ). Twelve studies used F2F for courses other than special education (see    -    ). Although the level(s) of special courses was/were not specified, the courses targeted the undergraduate and graduate level. The undergraduate courses comprised the topics of geology, geography, marketing management, health science, calculus, and chemistry; the graduate course taught research methods for 80 students.
Professional development programs were described in studies as having been designed and utilized for faculty (see   ), disability providers (see ), administrators (see ), and teachers (see ). Two programs were described as F2F (see  ) while three were web-based (see   ). In Zhang’s  study, for example, faculty and teachers were teamed to implement a collaborative UDL solution. Topics included UDL approaches, accessibility, accommodation, and disability laws and regulations. Overall, 16 of the 17 studies described UDL-based implementations.
3.3. Independent and Dependent Variables
Regarding UDL implementation, a variety of independent variables were identified. Eleven studies described investigations focused on increasing learning outcomes. The most frequently used independent variables were UDL-based course design and implementation (see    ). Multiple variables were used only once, which included captioned conditioning (see ), assignment activities related to revision of lesson plans (see ), action research and practicum (see ), UDL training for instructors (see ), traditional course revision (see ), lecture on the lesson plan revision (see ), and peer-led team learning (PLTL) implementation (see ).
Implementation for faculty members took the form of professional development programs, with each study using a different type of program. The independent variables included keynote presentation on UDL and focus group discussion (see ); implementation of five instructional modules, including accommodation, UDL, web accessibility, college writing, and climate assessment (see ); intensive workshops (see ); an online disability awareness program (see ); and instruction using the collaborative professional development model and UDL strategies (see ).
Multiple dependent variables were also measured. Six studies evaluated UDL-implemented courses using course evaluations (see      ), which included measures of effectiveness, flexibility, learning outcomes, course accessibility, and accommodations. Other measures focused on the degree of the instructor’s social presence (see ). These included interactions with the instructor in and outside the class with immediacy; the number of class interactions using technology and discussion (see   ); the relationship between use of technology and grades or learning (e.g., the relationships between the frequency of using tools and academic scores, see ) and products. The products were made by the students as the effect of the UDL implementations. These products included the revision of lesson plans (see ), development of the modified lesson plans (see ), GPA (see ), and preservice teachers’ UDL implementation in their own classes (see ). Studies also collected and analyzed preservice teachers’ reflections on their perceived level of knowledge acquisition on UDL implementation from the courses as a transformative pedagogy for diverse students (see  ).
Furthermore, perceptions of UDL implementation, participants’ discussions, confidence in UDL implementation, attitudes and actions toward SDs, effectiveness of the programs, knowledge about UDL, accommodations and disability-related issues, and level of knowledge acquisition were commonly measured across the studies using professional development programs (see     ). Finally, preferred training subjects and program delivery modes were also explored (see ).
3.4. Implementation Strategies
Regarding strategies, nine studies delineated or listed UDL approaches matching UD or UDL principles (see         ). Three principles were sustained in each study using various strategies. These strategies included web-based computer-mediated communication, provision of text, audio, and video learning materials, discussion, web-based class management systems, interaction with technologies, team collaboration strategies, and learning community (see    ). Traditional instruction was also used (see  ). Furthermore, group or individual assignments and hands-on activities were employed to enhance the principles of multiple expression and engagement (see   ). Course modifications in some studies were made based on student feedback (see  ), while for professional development programs, “anywhere and anytime” web-based instruction, web-based workshops, and web-based information were generally utilized (see   ).
3.5. Effectiveness of Implementation
Implementation of the interventions was generally reported to be effective. The outcomes of captioned conditioning (see ) and revision of the lesson plans (see ) were reported effective with statistically significant differences for effect sizes from the control/experimental group comparison. The outcomes from the studies using pre- and posttests (see   ) were also reported effective with statistical significance. Improvement was reported in the following areas: application of learning strategies of students with LD and ADHD across two semesters (see ); participation in discussion, interaction with technology, and reflection skills (see   ); and confidence in technology skills (see    ).
This systematic review revealed that the outcomes of UDL implementation in 15 of the 17 studies examined were effective for coursework or professional development programs. This finding is promising, suggesting the value of applying UDL principles  .
Specifically, the studies reflected different aspects of UDL implementation, including interaction, knowledge acquisition, technology use, modification and accommodation for SDs, and related laws and regulations  . The studies also offered different perspectives and learning outcomes for both professionals and students at the postsecondary level (faculty, teachers, service providers, or administrative staff and students). In this context, effectiveness of UDL implementations was found among both groups. The studies that used group comparison between experimental and control groups found statistically significant differences between them, consistent with the larger body of research  . Furthermore, the studies using pre- and posttests found significant improvements between training with and without implementation, likewise aligned with the group comparison studies (see   ). Finally, the results from the comparison studies addressing the importance of teacher education were consistent with those of existing studies  and across the studies included in this review (see     ), further indicating the overall value of UDL at the postsecondary level.
Of particular importance was the finding that participants with LD and/or ADHD did not perform better in their STEM courses than their peers with other disabilities who did not participate in PLTL. As a result, further research should address these findings with a particular focus on examining different disabilities, at-risk groups on campus, and other identified variables .
Also, of importance, three studies discussed students’ use of products to evaluate the effectiveness of the UDL implementation. The results suggested that the best approach was comprised of professors’ instruction with examples, students’ practice and products using hands-on activities, and feedback and assessments (see   ). These findings are aligned with the other studies in this review, showing student preference for in-house teacher-made instructional materials over commercial materials  and the effectiveness of hands-on activities   . Overall, processes of instruction were aligned with one of the evidence-based practices in other disciplines  . That is, behavior skills training comprised of instruction, rehearsal, and feedback. Behavior skills training is generally used for teachers and students in the training of individuals with developmental disabilities.
It is also important to emphasize that less than 5% of the participants sampled in the 17 studies were reported to have disabilities. This might explain the discrepancy in the number of enrollments and class attendance rates for these students (see  ), which was aligned with existing reports   . Although SDs were not representative, by and large, information from the participants suggests that UDL application was effective for all students sampled, whether they had disabilities or not. These are findings consistent with existing research .
The review also revealed that teacher education courses were described in some of the studies as involving students with and without special needs (see   ), in practicum (see ), and in teacher education courses (see  ), thus, offering examples of special education teachers’ training for SDs in K-12 settings. Extrapolated, these findings may suggest that information about UDL and related strategies should be taught to pre- and inservice teachers to improve instruction and learning outcomes as part of their teaching practices―a conclusion that is supported by and aligned with findings reported in the literature  .
Another finding is the importance of considering students’ needs when providing instruction and accommodations. In Smith  , students listened to in-class lectures more than using other accommodations to learn and study. At the same time, they least utilized a speech-to-text device to learn and study. This finding is aligned with other investigations, such as that of Black et al.  , in which SDs reported inappropriate accommodations and mismatches between their needs and accommodations or modifications provided. While this may be viewed as a finding emerging from this investigation at the postsecondary level, such a discovery has been addressed in secondary education  , revealing an important implication for the provision of accommodations and modifications.
The instructional strategies were found to match UD or UDL principles across the included studies. The strategies were nested in eLearning (e.g., web-based asynchronous vs. synchronous discussion; distance learning for two different classrooms at two different institutions; anytime-, any place-based), adult learning (e.g., learning autonomy, self-discipline), and traditional learning (e.g., in-class lecture). One of the strengths of web-based instruction is its flexibility in terms of time and space to promote learning as well as its inherent ability to handle built-in accommodations and modifications  . Most of the courses described in the 17 studies utilized web-based management systems, although some also included F2F instruction. It is, therefore, reasonable to conclude that web-based instruction or eLearning could be applied as an effective delivery mode of UDL implementation to enhance built-in accessibility. This may be viewed as a new finding resulting from this investigation. As stated, delivery modes were viewed in this review as one of the built-in mechanisms of UDL practice but have been mostly excluded as such in the existing research.
Finally, the most frequent independent variables were design and implementation of UDL-based courses. Other independent variables included strategies to facilitate UDL implementation, such as revisions and modifications of lesson plans; training instructors to enhance learning outcomes and interaction; use of technology; and learning community. All in all, the findings reinforce the value of UDL-based blended instruction, focusing on the three UDL principles of multiple means of representation, expression, and engagement.
This systematic review examined 17 empirically based studies focused on UDL implementation, presenting a discussion on the value of UDL supported by existing research. Altogether, the analysis revealed that these studies, conducted on the application of UDL principles, showed that this approach was effective; thus, underscoring the benefits of UDL in educating students with and without disabilities at the postsecondary level.