Interactive and Accessible? A First Insight into the Analysis of Digital Textbooks with regard to their Current Development Status

141 In B. Pepin, I. Kohanová, & M. B. Langfeldt (Eds.), Proceedings of the Fifth International Conference on Mathematics Textbook Research and Development (pp. 141–148). Norwegian University of Science and Technology. INTERACTIVE AND ACCESSIBLE? A FIRST INSIGHT INTO THE ANALYSIS OF DIGITAL TEXTBOOKS WITH REGARD TO THEIR CURRENT DEVELOPMENT STATUS Maxim Brnic and Gilbert Greefrath University of Münster, Germany This study examines the state of the art of digital mathematics textbooks, focusing on the implementation of interactivity and customisation options as key features of modern digital textbooks. This is done in the context of accessibility, which is regulated in the European Union for digital textbooks and can be beneficial for all students in the context of Universal Design for Learning. In a first step, the most up-to-date digital textbooks used in Germany in the 7th grade are examined. The study shows a discrepancy between potential digital improvements and their actual implementation. There are only a few interactive visualisations and task formats in the digital textbooks and hardly any individual customisation options, which are particularly relevant for accessibility. MOTIVATION State-of-the-art digital mathematics textbooks integrate new technical possibilities to promote the learning and teaching of mathematics. We understand digital mathematics textbooks of the latest generation (see Pepin et al., 2015) as follows: “A digital mathematics textbook is a technology-based curriculum resource for learning and teaching mathematics. It provides enhancement features, such as interactive and multimedia elements, feedback options, adaptivity, and customisation features that distinguish it from a printed textbook.” (Brnic et al., 2024) Initial studies show the benefits and effectiveness of such digital textbooks and comparable digital curriculum resources compared to printed materials (e.g., Brnic et al., 2024). The advantages of digital mathematics textbooks are attributed in particular to their potentials, such as the integration of interactive elements and digital feedback in the sense of scaffolding. However, digital mathematics textbooks offer even more opportunities, such as the inclusion of customisation options, new possibilities for collaborative work or ecological advantages (Choppin et al., 2014). Digital mathematics textbooks thus offer the opportunity to implement innovative technical possibilities and thereby change the way students approach mathematics (Rezat et al., 2021). The question arises as to what extent such enhancement features are implemented in current digital textbooks. This is where the European project Digital Education Material (DEM) comes in. The DEM project pursues three principal objectives. Firstly, digital textbooks are being Brnic & Greefrath ICMT5 – 2025 142 tested for their current state of development and for their accessibility. Accessibility means that a digital textbook and its functions can be used by all students. For example, students with disabilities, such as visual impairment or mobility issues, should be able to fully access and use the digital mathematics textbook used in class. Subsequently, comprehensive guidelines will be developed for designing a digital textbook that is accessible and includes enhancement features. Finally, based on the guidelines, initial prototypes will be developed. The study presented here can be assigned to the first objective, the textbook analysis. In this analysis, the interactivity of digital textbooks as a central distinguishing feature compared to printed textbooks and customisation options as a decisive aspect of accessibility are investigated in the first step. INTERACTIVITY IN DIGITAL TEXTBOOKS In contrast to printed textbooks, which consist of static elements such as images and text, digital textbooks can also integrate interactive elements. Interactive elements are those that are characterised by “responsiveness to the learner's action during learning” (Moreno & Mayer, 2007, p. 310). Such interactive features in digital textbooks include, for example, task formats and visualisations that react to user input (Usiskin, 2018). In particular, visualisations help to illustrate mathematical concepts and promote the exploration and understanding of mathematics (Tversky et al., 2002). Furthermore, meta-studies have already shown that dynamic visualisations in particular support learning more than static visualisations (Berney & Bétrancourt, 2016). Interactive elements in digital learning environments can be classified into three main types: interactivity by dialoguing, manipulating and controlling (Moreno & Mayer, 2007). Interactivity by dialoguing means that learners receive direct feedback or additional information in response to their input. In a digital textbook, this can be realised through interactive task formats, such as drag-and-drop tasks or tasks in which the solution can be entered. A second type of interactivity is manipulating, in which learners can set parameters or move objects. This is typical for so-called interactive dynamic visualisations (Rolfes et al., 2020), in which learners have a certain amount of control over the respective representation. For example, apps can be integrated into a digital textbook in which the visualisation can be changed using sliders or on-screen input. The third type of interactivity is controlling, i.e., the learner can set the speed or order of what is presented. This type of interactivity can be implemented in linear dynamic visualisations, such as films that represent a dynamic process and have pause/play options or can be played at different speeds (Moreno & Mayer, 2007; Rolfes et al., 2020). CUSTOMISATION AND ACCESSIBILITY OF DIGITAL TEXTBOOKS Aspects of controlling, such as speed adjustment or on/off functions, but also the possibility of individual settings, not only represent the potential of digital textbooks (Choppin et al., 2014), but also already meet criteria for an accessible digital textbook (UNICEF, 2019). An accessible digital textbook means that “learners who are blind/have low vision, those who are deaf/hard of hearing, those who have Brnic & Greefrath ICMT5 – 2025 143 intellectual/developmental disabilities, learning disabilities, or those who prefer to access information in ways different from visual inputs“ (UNICEF, 2019, p. 8) can also access a digital textbook. The technical possibilities of digital textbooks offer particular potential in this respect compared to printed textbooks. The first attempts to develop criteria for accessible digital textbooks refer to the Universal Design for Learning (UDL) framework (CAST, 2024). In terms of digital textbooks, the idea is not to create several parallel versions of a book, e.g., special editions for students with visual impairments, as is often the case at present. Instead, the aim is to use the UDL to create one version of a textbook that can be used by all learners, taking into account multiple means of representation, action & expression and engagement in the design process (CAST, 2024). In terms of digital textbooks, this means that functions are integrated that allow individual settings to be made, such as text adjustments or speed control of interactive features, but also, for example, the implementation of subtitles for videos (for further suggestions, see UNICEF, 2019). Accessibility of digital textbooks is not just a ‘nice-to-have feature’ and a potential of digital textbooks but is now required by the European Accessibility Act (Directive 2019/882). This European directive requires certain services and products to be provided in an accessible way. The rules apply specifically to digital technologies, so that e-books and digital textbooks must also be accessible. The European Accessibility Act is linked to the Convention on the Rights of Persons with Disabilities (United Nations, 2006 Article 24), which has been ratified by almost all states and declares that persons with disabilities should not be excluded from education and should receive appropriate support. Despite the relevance of the accessibility of digital textbooks, there is little research on the current state of development, design or use of digital accessible mathematics textbooks. THE PRESENT STUDY The study presented here is part of the multi-stage DEM project. In the first project phase, current digital textbooks are examined in terms of their state of development. The analysis is based on a catalogue of criteria developed in the project (see Digital Educational Material (DEM), 2025). The following two research questions, which provide an initial insight into textbook analysis, are derived from these criteria and from the importance of interactivity and customisation options with regard to the educational potential and accessibility of digital textbooks: To what extent are interactive elements already implemented in digital textbooks (RQ1)? To what extent are customising elements already implemented in digital textbooks (RQ2)? Method This study examines digital textbooks for mathematics teaching and learning. Therefore, the latest versions of digital textbooks for the seventh grade in Germany are compared with each other. To ensure that the textbooks are based on the same curriculum, the selection was limited to one grade and the version for the federal state of North Rhine-Westphalia was always selected. Accordingly, these are officially approved textbooks that are freely available on the textbook market. To take into Brnic & Greefrath ICMT5 – 2025 144 account different textbook concepts and to get a broad overview, a total of six different textbooks from the three largest textbook publishers (Klett, Cornelsen, Westermann) were selected, which sell a large proportion of textbooks in Germany. First, one textbook was selected from each publisher that emphasises differentiation and heterogeneous learning groups. These are textbooks that are particularly advertised for comprehensive schools (German Gesamtschule) where all school-leaving qualifications can be achieved. In addition, one textbook was selected from each publisher that is designed for the highest school type, i.e., the German Gymnasium (grammar school). The textbooks are always the student versions, as the functionalities for these are the focus of the study. The textbook analysis was conducted using qualitative content analysis (Mayring, 2015). The categories were developed and discussed within the DEM project group on the basis of the literature (see category system: Digital Educational Material (DEM), 2025). Regarding RQ1, each of the three types of interactivity – dialoguing, manipulating, and controlling – was examined. Therefore, these types of interactivity were subdivided into specific and distinct categories that illustrate the potential of digital textbooks: linear-dynamic visualisations (controlling interactivity) and interactive-dynamic visualisations (manipulating interactivity) as well as interactive task formats (dialoguing interactivity) (see Moreno & Mayer, 2007; Rolfes et al., 2020). In relation to RQ2, a distinction is made between options for customising the interactive elements examined in RQ1 and customising text settings in digital textbooks. The option to adjust the text to individual perceptions is a central UDL guideline (CAST, 2024; UNICEF, 2019). This study specifically examines the extent to which there are setting options for typography, including font, font size, line spacing (leading), character spacing (kerning), line length, text alignment, colour, and text structure (see Digital Educational Material (DEM), 2025). RESULTS AND DISCUSSION The textbook analysis is presented in Table 1, sorted by textbook, interactivity and customising. For each textbook, the type of school for which it is mainly designed is also indicated. The interactive elements are always provided in each textbook as additional materials or as links. This can be attributed to the fact that none of the textbooks was developed as a digital-only textbook. In all cases, the printed textbook was converted into a digital reader, comparable to a PDF file, and then additional material was added. It is also noticeable that although there are some examples of interactive elements, there is no great variation in the interactive elements between textbooks or even within a textbook. This becomes clear, for example, through the integrated videos, which are the only linear dynamic visualisations. These videos are designed to be used as instructional videos in all textbooks, to supplement definitions or sample problems. Brnic & Greefrath ICMT5 – 2025 145 Interactivity Customising Textbook Linear dynamic visualisations Interactive dynamic visualisations Interactive task formats Text (Typography) Interactive elements Lambacher Schweizer (Gymnasium) 58 instructional videos (of which 10 videos have integrated interactive task formats) None 17 task generators (each generator creates any number of tasks for one specific task type; option to enter a solution number; student receives feedback on correct/incorrect; solution with single steps can be displayed) None Play/pause videos; switch full-screen videos on and off; move the video position on the screen; adjust the speed of videos Schnittpunkt Mathematik (Gesamtschule) 41 instructional videos (of which 10 videos have integrated interactive task formats) None 82 geometry exercises with a digital tool (student receives feedback on correct/incorrect; students can get hints) None Play/pause videos; switch full-screen videos on and off; move the video position on the screen; adjust the speed of videos Elemente der Mathematik (Gymnasium) 65 instructional videos 10 interactive visualisations (only to the chapter on angles) 36 blocks of 5 tasks (option to enter a solution number; tasks vary when a block is repeated; students receive feedback on correct/incorrect; solution with single steps can be displayed) None Play/pause videos; switch full-screen videos on and off; adjust the speed of videos Sekundo (Gesamtschule) 76 instructional videos None 12 drag-and-drop tasks; 7 tasks with an interactive coordinate system (for drawing a function); 121 tasks with the option to enter a solution number; 10 tasks in which the solution can be entered as text (for all these tasks, the solution can be checked for correct/incorrect or the solution can be displayed directly.) None Play/pause videos; switch full-screen videos on and off; adjust the speed of videos Fundamente der Mathematik (Gymnasium) 65 instructional videos (only as a YouTube link; not directly integrated into the textbook) None None None None Dreifach Mathe (Gesamtschule) 142 instructional videos None None None Play/pause videos; adjust the speed of videos Table 1: Results of the textbook analysis. Brnic & Greefrath ICMT5 – 2025 146 A few videos in the two textbooks Lambacher Schweizer and Schnittpunkt Mathematik from Klett stand out here. These videos have integrated interactive task formats, i.e., the learner is asked to enter his or her solution to tasks discussed into the video. Interactive dynamic visualisations can only be found in one book. Such promising visualisations, which offer possibilities for interactivity by manipulation (Moreno & Mayer, 2007), are therefore rarely integrated. Four of the six textbooks also integrate different interactive task formats, which distinguishes them from a printed textbook (Usiskin, 2018). However, most of the formats only require a single number as the solution input. Only the Sekundo textbook integrates different types of such dialoguing interactivity. It should be emphasised that students can not only check their solutions, but also often receive help with incorrect solution inputs. However, this is usually a general form of help that does not address the students’ misconceptions and thus corresponds to complex, elaborated feedback (Shute, 2008). The only customisation options for interactive elements relate to the integrated videos. Options such as play/pause or speed control represent the typical features for interactivity by controlling. With regard to the text layout, no global typographic adjustments can be made, such as adjusting font settings. The text can only be zoomed in or out. The text is not responsive in any of the textbooks, and the quality of the font deteriorates when zoomed in. This means that even such simple features that would make a textbook more accessible are missing. A key aspect of an accessible, digital textbook that follows the UDL Guidelines is to adapt the design to the perception of the respective user (see CAST, 2024; UNICEF, 2019). CONCLUSION AND OUTLOOK Overall, it can be said that the potential of digital mathematics textbooks in terms of interactivity is hardly used (RQ1) and that digital textbooks hardly meet criteria for accessibility in terms of customisation options (RQ2). The fact that the investigated digital textbooks are characterised as digitalisations of the printed textbook, which are only offered with additional materials, also hardly changes the representation of the content (cf. Rezat et al., 2021). Since publishers often adhere to the classic structure of printed books, technical possibilities for interactive functions and individual adaptations are rarely exploited. Although promising tools or dynamic visualisations can already be found in digital textbooks, they are usually only used as supplementary material and only in limited sections. The design of digital textbooks and the implementation of interactive elements could be consistently developed in line with the principles of UDL (see CAST, 2024). This approach not only aims to make better use of the potential of digital textbooks – such as fostering interest and motivation in learning – but also to address the diverse individual needs of students. This could be achieved by providing alternatives, offering choices, and purposefully varying interactive elements that align with UDL principles, thereby creating learning materials that are accessible to everyone. The results of the study are particularly noteworthy given that the study examined the latest versions of the textbooks that are used in Brnic & Greefrath ICMT5 – 2025 147 mathematics classes, and that the accessibility of digital textbooks needs to be implemented by a European directive. Furthermore, it can be assumed that not only students with disabilities benefit from a well-designed textbook, but that the individual needs of all students are addressed. It is important that a textbook does not lose accessibility when its enhancement features are expanded. In the study presented here, only individual aspects of the accessibility and potential of digital textbooks have been examined so far. In the further textbook analysis, further aspects will be included, such as the integration of feedback or opportunities for cooperation and further accessibility aspects (see Digital Educational Material (DEM), 2025). In addition, textbooks from primary school will be compared with those from secondary school and textbooks from other European countries will be analysed. Based on the textbook analysis, guidelines for accessible digital textbooks will be developed and prototypes will be designed with the help of these guidelines. The project brings together technical and educational perspectives to address the research gap on accessible, advanced digital textbooks. ACKNOWLEDGEMENTS AND FUNDING The study is part of the project Digital Education Material (DEM) which is Co-funded by the European Union (Project Reference: 2023-1-LU01-KA220-SCH-000152286). We would like to thank our project partners at CDV Luxembourg, Free University of Bozen-Bolzano, Graz University of Technology, University of Hamburg and University of Vechta. REFERENCES Berney, S., & Bétrancourt, M. (2016). Does animation enhance learning? A meta-analysis. Computers & Education, 101, 150–167. https://doi.org/10.1016/j.compedu.2016.06.005 Brnic, M., Greefrath, G., & Reinhold, F. (2024). Working with digital textbooks or printed materials: A study with boys and girls on conditional probability. ZDM – Mathematics Education, 56(4), 559–572. https://doi.org/10.1007/s11858-023-01543-x CAST. (2024). Universal design for learning guidelines version 3.0. https://udlguidelines.cast.org Choppin, J., Carson, C., Borys, Z., Cerosaletti, C., & Gillis, R. (2014). A typology for analyzing digital curricula in mathematics education. International Journal of Education in Mathematics, Science and Technology, 2(1), 11–25. Digital Educational Material (DEM). (2025). Kriterienkatalog für die Analyse digitaler Schulbücher: Barrierefreiheit, Didaktik, Technik, Design Version 03/2025 [Criteria catalogue for the analysis of digital textbooks: accessibility, didactics, technology, design Version 03/2025]. Graz University of Technology. https://doi.org/10.3217/WQGPCHF622 Brnic & Greefrath ICMT5 – 2025 148 Mayring, P. (2015). Qualitative content analysis: Theoretical background and procedures. In A. Bikner-Ahsbahs, C. Knipping, & N. Presmeg (Eds.), Approaches to Qualitative Research in Mathematics Education (pp. 365–380). Springer Netherlands. https://doi.org/10.1007/978-94-017-9181-6_13 Moreno, R., & Mayer, R. (2007). Interactive multimodal learning environments. Educational Psychology Review, 19(3), 309–326. https://doi.org/10.1007/s10648-007-9047-2 Pepin, B., Gueudet, G., Yerushalmy, M., Trouche, L., & Chazan, D. (2015). E-textbooks in/for teaching and learning mathematics: A disruptive and potentially transformative educational technology. In L. D. English & D. Kirshner (Eds.), Handbook of International Research in Mathematics Education. (3rd ed., pp. 636–661). Routledge. https://hal.archives-ouvertes.fr/hal-01207678 Rezat, S., Fan, L., & Pepin, B. (2021). Mathematics textbooks and curriculum resources as instruments for change. ZDM – Mathematics Education, 53(6), 1189–1206. https://doi.org/10.1007/s11858-021-01309-3 Rolfes, T., Roth, J., & Schnotz, W. (2020). Learning the concept of function with dynamic visualizations. Frontiers in Psychology, 11, 693. https://doi.org/10.3389/fpsyg.2020.00693 Shute, V. J. (2008). Focus on formative feedback. Review of Educational Research, 78(1), 153–189. https://doi.org/10.3102/0034654307313795 Tversky, B., Morrison, J. B., & Betrancourt, M. (2002). Animation: Can it facilitate? International Journal of Human-Computer Studies, 57(4), 247–262. https://doi.org/10.1006/ijhc.2002.1017 UNICEF. (2019). Accessible digital textbooks using universal design for learning. UNICEF. United Nations. (2006). Convention on the rights of persons with disabilities. Usiskin, Z. (2018). Electronic vs. paper textbook presentations of the various aspects of mathematics. ZDM – Mathematics Education, 50(5), 849–861. https://doi.org/10.1007/s11858-018-0936-2