A User Study to Evaluate Tactile Charts with Blind and Visually Impaired People

Abstract

Charts, for example bar or line charts, represent data visually. They make use of domain specific skills of the visual sense like fast pattern recognition. Tactile charts enable blind and visually impaired people to access charts by the sense of touch. Their design differ from visual chart design. It is unclear how effective design of tactile charts looks like for different chart types. That is why we conducted a remote user study with 45 blind and visually impaired people to investigate several design criteria for tactile charts. Therefore, we have mailed tactile charts to participants who evaluated the charts on the basis of an online survey. In this paper, we analyze four comparison tasks with two bar charts, line charts, scatter plots, and pie charts, that differ in one specific design criteria - in particular, inner and outer helplines in bar charts, the design of grid lines in line charts, the use of grid lines in scatter plots, and the usage of textures in pie charts. We compare these charts regarding the computed error rate, the number of correct answers as well as a rating given by participants.