Haptic Graph

A haptic graph is a non-visual rendering of a chart or graph — a bar chart, line graph, scatter plot, or mathematical function — that a blind or low-vision user explores by touch, typically through a force-feedback haptic device such as the PHANToM or a vibrotactile tablet. Magnitude is encoded through some combination of physical displacement (taller walls for larger values), surface texture, friction, vibration amplitude or frequency, and sound. Haptic graphs are a long-standing accessibility research target because they offer a plausible alternative to tactile swell-paper diagrams, which are costly to produce and cannot be easily updated. Research on haptic graphs has repeatedly highlighted cognitive-load challenges in integrating multiple haptic contacts over time, and has motivated careful study of which haptic properties best encode which types of data.