Paper Reading #29: Usable Gestures for Blind People, Understanding Preference and Performance

Shaun K. Kane and Jacob O. Wobbrock represented the Information School of the University of Washington.
Richard E. Ladner represented the Computer Science & Engineering school of the University of Washington.

This paper was presented at CHI 2011.

Summary


Hypothesis
In this papers, researchers attempted to show how blind people interact with gestures on a touch screen device as well as which gestures they prefer.

Methods


This research was broken into two separate studies.

For the first study, the blind participants were asked to invent their own gestures that could be performed on a tablet PC. 20 Participants were recruited for this experiment: 10 people were blind and 10 had sight.  The sight group was used as a baseline to compare against.
The participants, once oriented with the screen, were asked to perform to gestures to complete a list of tasks. Some of these tasks: undo, move up, delete, etc etc.

Each participant created two gestures per command.

The next study was focused on gesture performance. The blind participants and sighted participants were asked to perform the same gestures as a way to ascertain which gestures were easier or more effective for the blind to perform.

They were also asked to rate the easiness of the following gestures: tap, flick, multi-touch, shape, symbol.

Results
For the first study, they found that most of the gestures created by the blind group were more metaphorical and abstract than the sighted group. The blind group also used landmarks or the assumption of a given physical space. For example, they made the "control-v" finger tap movement for the past command.

They also found that the blind group preferred landmarks or performing gestures close to the screen.

In the second study, the blind group was found to prefer multi-touch gestures much more than the sighted group. They also slightly preferred the flick.

Discussion
This is definitely related to the previous reading that we did this week. However, the important distinction is that a blind group was asked to create and rate gestures. The previous research indicated that the preferred and most efficient gesture was the bezel mark. The Blind group also preferred bezel gestures so perhaps maybe in future mobile input, bezel gestures will be used more for both blind and sighted users.