Online Nemeth Braille Input/Output Using Content MathML
Samuel S. Dooley, Susan Osterhaus, Dan Brown, Edgar Lozano, Su H. Park · 2016 · Proceedings of the 13th International Web for All Conference (W4A) · doi:10.1145/2899475.2899512
Summary
This extended abstract presents a software system that enables automatic two-way conversion between printed mathematical notation and Nemeth Braille, using Content MathML as an intermediary representation. Access to mathematical content remains one of the most challenging barriers for visually impaired students in STEM education — producing braille mathematics materials is expensive and time-consuming, and backward translation from Nemeth Braille to print math is difficult even for specialist teachers of the visually impaired. The system extends an existing WYSIWYG equation editor by adding Nemeth Braille as an output format alongside Presentation MathML. Content MathML serves as the common structural representation because its operator-based design aligns well with Nemeth Braille encoding rules, which are largely structural in nature. The system handles both straightforward structural transformations (mathematical operators, comparison signs, special symbols) and contextual encoding rules that require specialised processing, such as nested structure indicators for fractions and radicals, superscript/subscript combinations, spacing rules, and numeric and alphabetic indicators. For input, the system accepts braille cell events from refreshable braille devices encoded as ASCII braille, routing them through the same key-based transformation framework used for QWERTY keyboard input, augmented by a finite-state machine to handle multi-cell Nemeth input sequences.
Key findings
The system was validated through 948 separate test cases verified by a blind tester within two days, who compared hand-generated alternate text descriptions against machine-generated braille output and provided specific feedback for improvements. This rapid validation demonstrates both the system's reliability and the efficiency of the testing approach. A key technical insight is that Content MathML provides an effective bridge between visual and tactile mathematical representations because both Nemeth Braille and Presentation MathML can be generated from it using the same operator-based transformation framework. The system enables real-time, simultaneous display of mathematical expressions in both print and braille formats, updated with each keystroke — meaning a sighted instructor and a braille-reading student can communicate mathematics online and instantaneously. The bidirectional input capability means both QWERTY and braille keyboard inputs feed into the same equation editor instance, creating a truly shared workspace.
Relevance
This work addresses a critical and underserved area of digital accessibility: mathematical content for visually impaired students. As STEM education increasingly moves online, the gap between what sighted and visually impaired students can access widens. Traditional braille math production is slow, expensive, and requires specialist knowledge, effectively excluding many visually impaired students from mainstream STEM classrooms. By automating both print-to-braille and braille-to-print mathematical translation in real time, this system has the potential to fundamentally change how visually impaired students participate in mathematics education. The real-time bidirectional communication capability is particularly significant — it enables the kind of interactive, immediate mathematical discourse that sighted students take for granted but has been largely unavailable to braille readers in online learning environments. For accessibility practitioners, this work highlights that mathematical accessibility requires domain-specific solutions beyond general web accessibility guidelines, and that MathML provides the semantic foundation needed to support multiple accessible output formats.
Tags: braille · mathematics accessibility · STEM accessibility · visual impairment · MathML · equation editors · Nemeth Braille
Standards referenced: MathML