Access to inclusive and accessible teaching and learning materials is a prerequisite for equitable participation in education for learners with and without disabilities (UN 2008, Art. 24). In parallel with ongoing digitalisation processes, digital textbooks are increasingly used in European school systems and are often associated with enhanced learning opportunities through multimodality, interactivity, and individualization (Totter et al., 2023). However, these benefits can only be realised by all learners - particularly students with disabilities - if digital textbooks are designed to be consistently accessible. In addition, recent legal developments, such as the European Accessibility Act and corresponding national legislation (e. g. Germany: Barrierefreiheitsstärkungsgesetz), mandate the production and use of accessible digital educational materials (Marcus-Quinn, 2022).

Beyond technical implementation, the pedagogical and didactic design of accessible digital textbooks is of central importance. Universal Design for Learning (UDL) provides a well-established framework for the inclusive design of educational materials (UNICEF 2019). Originating in the United States and initially developed in the fields of architecture and product design, UDL was transferred to educational contexts in the 1980s. The framework assumes learner diversity as a starting point and aims to reduce learning barriers while maximizing educational participation for all learners (Meyer et al., 2014). UDL promotes the provision of multiple learning options aligned with learners’ individual needs and is structured around three core principles: (1) multiple means of engagement, (2) multiple means of representation, and (3) multiple means of expression (CAST 2024). These principles are directly applicable to the design of teaching and learning materials, including digital textbooks (Lanners, 2020; UNICEF, 2019; Wibowo et al., 2022).

To investigate the current state of digital textbooks in Europe, the Erasmus+ project Digital Education Material (DEM) was initiated (DEM 2026). The project consortium combined interdisciplinary expertise from schools and higher education institutions, including partners from Luxembourg (project coordination), Germany, Austria, and Italy, representing inclusive education, subject didactics (mathematics and geography), media education, and accessibility studies. Between 2023 and 2025, DEM conducted the first systematic evaluation of digital mathematics and geography textbooks used in primary and lower secondary education across four European countries. The overarching aim was to assess the quality of accessibility in existing digital textbooks and to generate sustainable impulses for future development. The project pursued three main objectives:

1. Systematic analysis of selected digital textbooks with regard to technical accessibility and subject-specific didactic quality
2. Development of a prototype for an accessible digital textbook
3. Provision of guidelines to support the sustainable production of accessible digital textbooks.

The DEM project employed a mixed-methods approach comprising scientific analysis, a systematic literature review, guideline development, and prototype implementation. 1. Scientific Analysis: A comprehensive criteria catalogue was developed to analyze digital textbooks from Luxembourg, Germany, Austria, and Italy. The catalogue was informed by established frameworks for inclusive and accessible learning materials, including the Web Content Accessibility Guidelines (WCAG) and UDL. It covered four dimensions: didactics, accessibility, design, and technology. Two structured checklists were used to assess both technical accessibility and pedagogical quality (DEM, 2025a, 2025b, 2025c). In total, 77 digital textbooks (44 mathematics, 24 geography) from primary and lower secondary education, published by ten different publishers, were analyzed between June 2024 and February 2025. To ensure comparability in light of evolving EU accessibility legislation, a detailed coding manual was developed. 2. Literature Review: A systematic literature review complemented the textbook analysis, focusing on empirical research on digital textbooks in mathematics and geography. A total of 782 publications were identified, including 62 from mathematics education and five from geography education. Accessibility-related aspects were addressed almost exclusively in mathematics education and typically only marginally. 3. Guideline Development: Based on analytical findings and iterative partner workshops, DEM developed evidence-informed guidelines for the design and production of digital, inclusive, and accessible textbooks. The process integrated transdisciplinary expertise from inclusive education, accessibility research, UX and interaction design, educational technology, and subject didactics. The guidelines address the entire development lifecycle -from inclusive learning objectives to content representation, interaction design, technical implementation, feedback, and quality assurance - explicitly operationalizing a Born Accessible approach aligned with UDL principles (Brnic et al., 2025). 4. Prototype Development: The guidelines were operationalized through four digital textbook prototypes in mathematics and geography for primary and lower secondary education. Each prototype includes an exemplary chapter with student and teacher versions and is openly licensed to enable reuse and adaptation.

The systematic analysis indicates that accessibility criteria—and thus UDL principles—are largely not implemented in current digital textbooks. Most analyzed textbooks represent digitized print versions rather than digital-born learning materials. None of the textbooks fully met established accessibility standards such as WCAG or PDF/UA, significantly limiting access for learners with disabilities and users of assistive technologies (e.g. screen readers). The prototype development demonstrates how UDL principles can be realized in accessible digital textbooks by enabling multimodal access to information (visual, auditory, and tactile), integrating feedback mechanisms, and supporting learners through scaffolding and AI-assisted features (Macchia & Torri, 2025). At the same time, the findings highlight challenges, such as increased cognitive demands resulting from expanded choice options and the context-dependent nature of didactic decisions (e.g. alternative text design). While the prototype illustrates the potential of UDL-based digital textbooks, further evaluation with students is required to assess usability and learning effects in authentic classroom settings.

Brnic, M., Degenhardt, S., Edelsbrunner, S., Erdel, T., Greefrath, G., Kargl, B., Lathan, H., Macchia, V., Mönter, L., Schön, S., Schütt, M.‑L., Torri, S., Wetzel, M. & Ebner, M. (2025). A digital textbook for everyone: Accessible and interactive, from concept to use. CDV. https://zenodo.org/records/18313228 https://doi.org/10.5281/zenodo.18313228 CAST. (2024). CAST Universal Design for Learning Guidelines version 3.0. https://udlguidelines.cast.org/ DEM. (2025a). Analyse von digitalen Schulbüchern auf Barrierefreiheit im Rahmen des Projekts DEM: Rohdaten. https://repository.tugraz.at/oer/s118t-56898 DEM. (2025b). Kodierhandbuch Analysebogen zum digitalen Schulbuch: Technik, Barrierefreiheit, Design Version 02/2025. https://repository.tugraz.at/oer/yzhp8-7ay47 DEM. (2025c). Kriterienkatalog und Rohdaten für die Analyse digitaler Schulbücher auf Barrierefreiheit: Didaktik, Version 07/2025. https://repository.tugraz.at/oer/qzp3g-1m819 DEM. (2026). Digital Education Material. https://www.dem-project.eu/ Lanners, R. (2020). Neue Lehrmittel im Universellen Design. Schweizerische Zeitschrift für Heilpädagogik, 26(10), 17–26-17–26. https://ojs.szh.ch/zeitschrift/article/view/895 Macchia, V. & Torri, S. (2025). Enhancing Inclusive Digital Textbooks with Artificial Intelligence: New Frontiers in Accessibility and Personalisation. Italien Journal of Special Education for Inclusion, XIII(1), 139–149. https://doi.org/10.7346/sipes-01-2025-11 Marcus-Quinn, A. (2022). The EU Accessibility Act and Web Accessibility Directive and the implications for Digital Teaching and Learning Materials. Routledge Open Research. Meyer, A., Rose, D. H. & Gordon, D. (2014). Universal design for learning: Theory and practice. CAST Professional Publishing an imprint of CAST Inc. Totter, A., Müller-Kuhn, D., Keller-Lee, M. & Rast, C. (2023). Digitales Schulbuch zwischen Nutzungspotenzial und Nutzungspraxis. MedienPädagogik: Zeitschrift für Theorie und Praxis der Medienbildung, 527–550. https://doi.org/10.21240/mpaed/jb20/2023.09.20.X UNICEF. (2019). Accessible Digital Textbooks using Universal Design for Learning: For Learners with and without disabilities. https://www.accessibletextbooksforall.org/media/1066/file/ UNICEF%2520ADT%2520Emerging%2520Lessons.pdf&ved=2ahUKEwj81OOst8yIAxVPVfEDHcenKyUQFnoECBUQAQ&usg=AOvVaw1T0Bb_rpiTDkWNfruOFE0z Wibowo, J., Schütt, M.‑L. & Bükers, F. (2022). Lernmaterialien im Sportunterricht. German Journal of Exercise and Sport Research, 52(4), 584–595. https://doi.org/10.1007/s12662-022-00839-6