Usability of accessible bar charts

Abstract

Bar charts are one of the most commonly used diagram types. Tactile diagrams are a widely used technique for presenting graphics to people who are blind. We explored how to present bar charts using a tactile presentation. Our user study used blind participants and evaluated both user preferences and performance. We found that providing grid lines and values in a tactile diagram was preferred to a direct transcription. In addition, presenting the data as a tactile table was preferred to a tactile chart. Both of these approaches reduced the error rate, and presentation as a table had performance benefits. We also investigated the comparative usability of: a tactile presentation, an audio description of the bar chart, and a tactile/audio presentation in which a tactile diagram is overlaid on a touch-sensitive device which provides audio feedback on demand. We found that tactile was the most preferred while audio was the least. © 2010 Springer-Verlag.