Paper Reading #29

Usable gestures for blind people: understanding preference and performance

 

Authors:	Shaun K. Kane	University of Washington, Seattle, Washington, USA
	Jacob O. Wobbrock	University of Washington, Seattle, Washington, USA
	Richard E. Ladner	University of Washington, Seattle, Washington, USA

Proceeding 

CHI '11 Proceedings of the 2011 annual conference on Human factors in computing systems 

Summary

• Hypothesis -The researchers believe blind and sighted people use touch interfaces differently. Using the differences in design practices can help different users with better gestures.

• Content - Four design guidelines were set for observation:

1. Avoid symbols in print writing - Blind people may not learn print as a form of input.
2. Favor edges, corners, and other landmarks - spatial orientation without sight can be replaced by relative positions, increasing gesture effectiveness.
3. Limit time-based gestures - Blind people take a longer time to perform gestures, so this could limit what they can do.
4. Reproduce traditional layouts when possible - familiar layouts such as QWERTY let blind people immediately know how to use an interface.

• Methods - 10 sighted and 10 blind people were asked to perform gestures in order to accomplish a task described by a moderator. After making two gestures, they were asked how effective they thought their gestures were on a Likert scale. The study was repeated but the participants were asked to perform the gestures they previously made and rate them again on a Likert scale.
• Results - Because of the lack of visual feedback, blind people found their gestures more fitting than sighted people based on their Likert responses. Also the gestures from blind people were considerably more complex, having more edges and taking a longer time to complete. They were also more likely to use multi-touch compared to sighted people. The gestures from blind people were also physically larger. Overall, blind people did not find their gestures easier, but in different tasks there were more variance. This means that some tasks are easier than others. 

Discussion
The researchers achieved their goal of understanding interaction with blind people reasonably well. Unfortunately the technologies created today have been built up for so long with visual feedback being an essential backbone, it is difficult to tell if blind people will ever have the same utility from technology. In the future, this issue could be solved by giving artificial sight, however that is far down the road.