Blog #29: Usable gestures for blind people: understanding preference and performance

Paper Title: Usable gestures for blind people: understanding preference and performance

Authors: Shaun Kane, Jacob Wobbrock and Richard Ladner

Author Bios:

Shaun Kane: is currently an Assistant Professor at the University of Maryland and holds a PhD from the University of Washington

Jacob Wobbrock: is currently a Professor at the University of Washington and holds a PhD in Mathematics from the University of California, Berkely

Richard Ladner: is currently a Professor at the University of Washington and holds a PhD in Mathematics from the University of California, Berkeley

Presentation Venue: CHI '11 Proceedings of the 2011 annual conference on Human factors in computing systems that took place at New York (ACM)

Summary:
Hypothesis: Blind people have different needs and preferences for touch based gestures as compared to sighted people. This paper aims to explore exactly what these preferences may be.

How the hypothesis was tested: In the first study both blind and sighted people were asked to invent a few of their own gestures that might be used to interact and conduct standard tasks on a computing device. Because visual results of commands would not be visible to all participants, the experimenter read a description of the action and result of each command. Each participant invented two gestures for each command and then assessed them based on usability, appropriateness, etc.

The second study was more focused on determining whether blind people simply perform gestures differently or actually prefer to use different gestures. In this study all participants performed the same set of standardized gestures. The experimenter described the gesture and its intended purpose, and the participants tried to replicate it based on his instruction.

Results: In the first study the experimenters found that on average, a blind person's gesture contains more strokes than a sighted person's. Additionally, blind people were also slightly more likely to make use of the edge of the tablet when positioning their gestures, as well as being more likely to use mili-touch gestures.

In the second study, there was no significant measure of difference in easiness between blind and sighted people. It was noted that blind people tended to make significantly larger gestures than sighted people, although the aspect ratio appeared consistent between the two groups. Additionally, blind participants took about as twice as long to perform the gestures, and their lines were often more "wavy" than those of sighted participants.

Discussion:
Effectiveness: I found this paper was very interesting and that the authors did a great job in achieving their goals. They performed their tasks in a very thoughtful and an organized manner. I would like to see this technology into effect!