Exploring New Paradigms for Accessible 3D Printed Graphs
Michele Hu · 2015 · ASSETS '15: Proceedings of the 17th International ACM SIGACCESS Conference on Computers & Accessibility · doi:10.1145/2700648.2811330
Summary
This paper explores novel approaches to representing bar graphs for blind users using 3D printing technology, moving beyond traditional flat tactile graphics. Traditional tactile graphics (created with swell paper, embossers, or thermoform) use raised lines and textures on flat surfaces, but research suggests that truly three-dimensional physical objects may convey information more effectively. The author developed and compared three paradigms for 3D-printed bar graphs: embossed graphs (similar to traditional tactile graphics), freestanding graphs with guidelines connecting bars to the y-axis, and freestanding graphs with tick marks directly on each bar. The research was grounded in curriculum analysis—examining New York State Common Core Mathematics standards and dozens of worksheets to identify that bar graph questions typically involve determining (1) trends and (2) specific y-values of bars. This informed the design focus: freestanding graphs could better convey trends through their shape, while various y-axis reference mechanisms could support value reading. The author employed a co-design methodology, working with two teachers for the visually impaired (TVIs) with 4 and 30 years of experience respectively, and one blind professional who works as an assistive technology coordinator and instructor. This approach ensured designs were informed by both pedagogical expertise and lived experience with tactile graphics.
Key findings
The co-design process yielded several important insights. First, simple bar graphs may not reveal the advantages of 3D representations—co-designers pushed for testing with more complex graphs (multiple datasets/colors) where traditional embossed approaches struggle. Second, texture is crucial for distinguishing datasets, with dot and line textures being easiest for blind students to differentiate. The blind professional emphasized that graph designs should require standard interpretation skills rather than providing shortcuts (like putting y-values directly on bar tops), though such shortcuts might be acceptable for students still learning graph interpretation. All co-designers agreed that tick marks projected onto bars were intuitive and convenient—when handed this prototype, the blind professional understood the concept immediately. Based on feedback, the "braille label on top" paradigm was eliminated, and the remaining three paradigms were developed into prototypes of increasing complexity: single-dataset bar graphs and double-dataset bar graphs (with line and dot textures on bar backs to differentiate datasets). The freestanding designs with guidelines or tick marks offer potentially significant advantages over traditional embossed representations for complex multi-dataset graphs.
Relevance
This research addresses a significant barrier in STEM education for blind students: access to data visualizations. While 3D printing has emerged as a promising technology for creating tactile graphics, simply translating visual conventions into three dimensions does not guarantee accessibility or usability. This work demonstrates the value of involving end users and domain experts (TVIs) in designing new tactile representations. The finding that freestanding 3D graphs with tick marks were immediately intuitive suggests that 3D printing enables design possibilities unavailable in traditional 2D tactile formats. For educators and accessibility professionals, the key insight is that 3D printed graphs should leverage the full dimensional space rather than merely replicating flat embossed graphics in a thicker medium. The emphasis on preserving standard graph interpretation skills (rather than providing "shortcuts") reflects pedagogical wisdom: accessible alternatives should build transferable skills, not create dependency on accommodation-specific formats. Future formal evaluation with blind students will determine which paradigms are most effective for different graph complexities.
Tags: visual impairment · tactile graphics · 3D printing · data visualization · STEM education · co-design · bar graphs