Sudoku Access: A Sudoku Game for People with Motor Disabilities
Stéphane Norte, Fernando G. Lobo · 2008 · Proceedings of the 10th International ACM SIGACCESS Conference on Computers and Accessibility (Assets '08) · doi:10.1145/1414471.1414502
Summary
This paper from the University of Algarve, Portugal presents Sudoku Access, an accessible version of the Sudoku puzzle game designed for people with motor disabilities. The system provides two alternative input methods: switch-based scanning and speech recognition, allowing users who cannot operate a conventional mouse or keyboard to play independently. The scanning system uses a hierarchical group-scanning approach where a single switch (or the Space key) cycles through groups of items — first selecting a Sudoku grid area, then narrowing to a row, then a cell, and finally selecting a number from an on-screen numeric keyboard. The speech recognition system, built on Microsoft's Speech Application Programming Interface (SAPI), allows players to specify row, column, and number values by voice. The game is highly configurable: users can adjust difficulty level, scanning velocity, number of repeat scanning cycles, scanning sound, scanning color, input device (mouse, switch, space key, or speech recognition), and Sudoku grid size (including 4x4 grids). All configuration options can themselves be controlled through scanning or speech, ensuring complete independence without assistant help.
Key findings
Usability tests were conducted with three middle school students (ages 13-15) with different motor disabilities. Jorge, a 15-year-old boy with no motor impairment but reluctance to use computers, used speech recognition to complete a 9x9 puzzle in 7 minutes 32 seconds by speaking 330 times, commenting: "With this Sudoku game I can use my voice to play and configure all the features just saying numbers." Fátima, a 13-year-old girl with Spina Bifida who uses a wheelchair, initially struggled with both the 9x9 grid complexity and speech pronunciation but succeeded with the 4x4 grid and a color-based alternative to numbers, completing it in 2 minutes 5 seconds with 275 Space key presses. Her feedback directly led to adding color-based and combined number-color modes. Daniela, a 14-year-old with progressive muscular paralysis who normally uses a webcam and on-screen keyboard, was excited to play independently using scanning, configuring the game herself and preferring colored cells. Satisfaction ratings across all three students were positive, with all rating the game as enjoyable, comfortable, and something they liked. The scanning sound was found to be particularly motivating, helping focus attention and causing students to treat the scanning process as part of the game itself.
Relevance
Sudoku Access demonstrates how accessible game design can serve dual purposes: entertainment and education. Sudoku develops logical thinking, concentration, and problem-solving skills — cognitive benefits that students with motor disabilities deserve equal access to. The participatory design approach, where Fátima's feedback directly led to the color-based mode, illustrates how user testing with the target population reveals needs that designers cannot anticipate. For accessibility practitioners, the system showcases several important principles: hierarchical scanning to reduce the number of switch activations needed, multiple alternative input methods to accommodate different abilities, comprehensive configurability of accessibility features, and the importance of ensuring that configuration settings themselves are accessible through the same input methods. The work also highlights that accessible games need not be separate or simplified — the core Sudoku puzzle remains unchanged; only the interaction method is adapted.
Tags: game accessibility · motor disability · scanning input · speech recognition · switch access · educational games · inclusive design · cerebral palsy · spina bifida