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Innovative Tool Enhances Tactile Graphics for the Visually Impaired

Bar graphs and various chart formats offer a straightforward method for presenting data; however, they can pose significant challenges for individuals who are blind or have low vision. Design professionals have made strides in creating tactile charts, yet the guidelines for this process can be overwhelming, as exemplified by the Braille Authority of North America’s extensive 426-page guide released in 2022. The creation of tactile charts often involves proficiency with multiple software programs, typically starting with tools like Adobe Illustrator before transitioning to another application for Braille translation.

Researchers from the Computer Science and Artificial Intelligence Laboratory (CSAIL) at MIT have introduced a transformative solution aimed at simplifying the tactile chart design process. Their new program, “Tactile Vega-Lite,” can convert data from standard sources, such as Excel spreadsheets, into both traditional visual charts and tactile formats. Built-in design standards help educators and designers swiftly produce accessible tactile charts without the burden of extensive manual adjustments.

This innovative tool has the potential to enhance the comprehension of various graphics for blind and low-vision individuals, such as bar charts that illustrate minimum wage comparisons across states or line graphs showcasing the fluctuation of GDP among countries over time. Users can easily modify their chart design within Tactile Vega-Lite and subsequently send the file to a Braille embosser to create a tactile representation.

During the upcoming spring season, the team will unveil Tactile Vega-Lite in a research paper presented at the prestigious Association of Computing Machinery Conference on Human Factors in Computing Systems. Lead author Mengzhu “Katie” Chen SM ’25 notes that the tool effectively balances the detailed requirements of design experts with the necessity for educators to quickly create tactile charts.

“We conducted interviews with teachers striving to make their lessons accessible and designers familiar with creating tactile charts,” explains Chen, who recently completed her master’s degree in electrical engineering and computer science. “Recognizing the different priorities of these groups, we developed a user-friendly program that provides immediate feedback during modifications while adhering to accessibility guidelines.”

Experiencing Data Through Touch

The foundation of Tactile Vega-Lite builds on the researchers’ earlier visualization tool, Vega-Lite. The new program automatically generates both a conventional chart and a tactile counterpart, designed to facilitate intuitive use without requiring users to navigate complex design decisions.

“Tactile Vega-Lite incorporates intelligent defaults that ensure correct spacing, layout, texture, and Braille conversion, adhering to best practices for tactile reading,” states senior author Jonathan Zong SM ’20, PhD ’24. He is also an incoming assistant professor at the University of Colorado and a fellow at the Berkman Klein Center for Internet and Society at Harvard University. “By leveraging pre-existing guidelines and insights from our interviews with experts, we aim for teachers or visual designers—regardless of their tactile design experience—to efficiently relay information in a format that is easily navigable for tactile readers.”

The program’s code editor allows for customization of axis labels, tick marks, and other chart components. Users can modify elements through simplified abstractions that summarize longer bodies of code. For example, adjusting how graph bars are filled can be achieved by changing the code from “dottedFill” to “verticalFill,” transforming the design from small circles to vertical lines.

To facilitate understanding of these abstractions, the researchers included a gallery of examples within the program. Each example delineates a phrase alongside the corresponding change in the graphical representation. Future improvements to Tactile Vega-Lite will aim to enhance the user interface to accommodate those less experienced with coding, potentially incorporating clickable buttons for modifications.

Chen and her team also aspire to integrate machine-specific customizations into Tactile Vega-Lite, which would allow users to preview the tactile chart prior to its creation by an embossing machine, enabling adjustments based on the particular device’s capabilities.

While Tactile Vega-Lite could significantly expedite the creation of tactile charts, Zong underlines the importance of having an expert conduct a final review for compliance with design guidelines. The researchers continue to refine the program by incorporating Braille design standards, though human oversight is expected to remain essential for ensuring quality.

“The capacity to create tactile graphics efficiently, especially without specialized software, is crucial for ensuring equitable access to information for tactile readers,” remarks Stacy Fontenot, owner of Font to Dot, who did not participate in the research. “Charts that adhere to current guidelines are vital for providing consistency, particularly for graphics rich in data. Tactile Vega-Lite offers an intuitive interface for rapidly and accurately developing quality tactile graphics, thereby decreasing the time required for designers to deliver these materials.”

The research team consisted of Chen and Zong, alongside Isabella Pineros ’23, MEng ’24, and MIT Associate Professor Arvind Satyanarayan, with their efforts supported by a grant from the National Science Foundation. Input was also gathered from Rich Caloggero of MIT’s Disability and Access Services and the Lighthouse for the Blind, allowing the team to observe real-world design workflows throughout the development process.

Source
news.mit.edu