The Tactile Graphics Helper

Abstract

Tactile graphics use raised lines, textures, and elevations to provide individuals with visual impairments access to graphical materials through touch. Tactile graphics are particularly important for students in science, technology, engineering, and mathematics (STEM) fields, where educational content is often conveyed using diagrams and charts. However, providing a student who has a visual impairment with a tactile graphic does not automatically provide the student access to the graphic's educational content. Instead, the student may struggle to decipher subtle differences between textures or line styles, and must deal with cramped and confusing placement of lines and braille. These format-related issues prevent students with visual impairments from accessing educational content in graphics independently, because they necessitate the students ask for sighted clarification. We propose a machine-vision based "tactile graphics helper" (TGH), which tracks a student's fingers as he/she explores a tactile graphic, and allows the student to gain clarifying audio information about the tactile graphic without sighted assistance. Using an embedded mixed-methods case study with three STEM university students with visual impairments, we confirmed that format-related issues prevent these students from accessing some graphical content independently, and established that TGH provides a promising approach for overcoming tactile-graphic format issues.