Non-Visual Feedback for Pen-Based Interaction with Digital Graphs

Access to simple visualisations such as bar charts, line graphs and pie charts is currently very limited for the visually impaired and blind community. Tangible representations such as heat-raised paper, and inserting pins in a cork-board are common methods of allowing visually impaired pupils to browse and construct visualisations at school, but these representations can become impractical for access to complex, dynamic data, and often require a sighted person’s assistance to format the representation, leading to a lack of privacy and independence. A system is described that employs tactile feedback using an actuated pin-array, which provides continuous tactile feedback to allow a visually impaired person to explore bar charts using a graphics tablet and stylus. A study was conducted to investigate the relative contribution of multimodal feedback (tactile, speech, non-speech audio) during typical graph browsing tasks. Qualitative feedback showed that the participants found it difficult to attend to multiple sources of information and often neglected the tactile feedback, while the speech feedback was the most popular, and could be employed as a continuous feedback mechanism to support graph browsing.