Haptic Comparison of Size (Relative Magnitude) in Blind and Sighted People
By Douglas, Sarah A.; Willson, Shasta; ASSETS 2007 - The Ninth International ACM SIGACCESS Conference on Computers and Accessibility, pp. 83-90Publication Date: October 15-17, 2007
Comparative study, using a haptic interface for human-computer interaction, to explore the perception of size in blind and sighted people. An experiment was conducted using the PHANToM haptic device in a virtual environment measuring human performance in judging relative magnitude with computer-generated haptic properties. Magnitude was represented by either physical length (displacement) or vibration varied by frequency or amplitude. Participants were 11 blind (6 female) and 11 sighted (5 female) individuals aged 18-60. Sighted participants were blindfolded. Each participant evaluated 33 trials composed of a base and a variant magnitude applied to two equidistant virtual haptic walls. In the displacement state, the height of the walls varied with magnitude; in the other states, touching the walls caused the PHANToM to vibrate at the appropriate frequency or amplitude. Results showed displacement tasks were 50% slower than vibration conditions for all participants. Accuracy for displacement and vibration varied by amplitude was equivalent. Vibration varied by frequency was significantly less accurate. Blind participants took 50% longer with equivalent accuracy to sighted participants. Sightedness had no effect on performance regarding the type of display. Thus, vibration varied by amplitude appeared to provide a faster and equally accurate display of magnitude compared with the traditional displacement approach, and benefited equally well visually disabled and sighted individuals.
Published by: Association for Computing Machinery (Website:http://www.acm.org)
SIGACCESS (ACM Special Interest Group on Accessible Computing) (Web Site: http://www.sigaccess.org )
