Usability of a multimodal videogame to improve navigation skills for blind children
Jaime Sánchez, Mauricio Sáenz, Miguel Ripoll · 2009 · Proceedings of the 11th International ACM SIGACCESS Conference on Computers and Accessibility (Assets '09) · doi:10.1145/1639642.1639651
Summary
This paper presents a usability evaluation of two complementary tools designed to help blind school-aged children develop orientation and mobility (O&M) skills in closed, unfamiliar spaces. The first tool is the Digital Clock Carpet (DCC), a custom-built haptic input device consisting of a wooden base with 12 tactile cells arranged like a clock face, each corresponding to a directional command. Children interact with it barefoot, using the clock metaphor (e.g., "go to 3 O'clock" means turn right) to learn spatial directions in a physically embodied way. The second tool is MOVA3D, a 3D videogame built with spatial sound that allows users to navigate virtual environments, find objects, and complete tasks using audio cues alone. The videogame was developed using a user-centered methodology with children aged 6 to 12 involved from the beginning of the design process. The study was conducted with students from schools for the blind in Santiago, Chile, and comprised three evaluation stages: a heuristic evaluation by five usability experts, an initial usability evaluation with 20 blind and low-vision students, and an end-user usability evaluation with 19 students using refined versions of both tools. Iterative redesign between stages addressed issues such as spatial sound clarity, key spacing on the carpet, and high-contrast visual options for children with low vision.
Key findings
The heuristic evaluation by five experts produced an average score of 3.8 out of 5, with strengths in content design (4.5), velocity and media (4.5), and recognition rather than recall (4.5), while visibility of system status (3.0) and error prevention (3.0) scored lowest. The main issue identified was unrestricted spatial sound causing confusion about object locations. In the initial usability evaluation with 20 children, the DCC received a mean appreciation score of 9.1 out of 10, and the videogame scored 7.35 out of 10, with children rating the activity as fun (9.9/10) and expressing immediate acceptance. The end-user evaluation with the redesigned tools showed high scores across all three dimensions: Satisfaction (9.2), Control and Use (9.2), and Sounds (9.2), with an overall mean of 9.1 out of 10. Differences between low-vision and totally blind users were not statistically significant, indicating that both groups found the multimodal interface usable and engaging. Children responded enthusiastically to the game format, with none finding it boring or tedious.
Relevance
This study demonstrates the potential of combining haptic and audio-based interfaces to teach real-world navigation skills to blind children through accessible gaming. The clock metaphor for directional input is an elegant, learnable solution that avoids dependence on visual interfaces entirely. For accessibility practitioners, the iterative user-centered design process is instructive — the researchers involved blind children throughout development and conducted multiple evaluation rounds, leading to meaningful improvements in spatial sound design and physical interface texture. The work also highlights the importance of providing both high-contrast visual modes for users with low vision and fully non-visual interaction for totally blind users within the same system. While the study is limited by its small sample size and the specific cultural context of Chilean schools, it provides a strong foundation for designing multimodal assistive technologies that are both functional and genuinely enjoyable for children.
Tags: blind children · orientation and mobility · haptic interfaces · audio interfaces · virtual environments · navigation · usability evaluation · assistive gaming