Paper Reading #24: Gesture avatar: a technique for operating mobile user interfaces using gestures

References

Hao Lu, Yang Li.  "Gesture avatar: a technique for operating mobile user interfaces using gestures". UIST '11 Proceedings of the 23rd annual ACM symposium on User interface software and technology.  ACM New York, NY, USA ©2011.

 Author Bios

Yang Li received his Ph.D. from the Chinese Academy of Sciences and conducted postdoctoral research at the University of California at Berkeley. Li helped found the Design Use Build (DUB) community while a professor at the University of Washington. He is now a Senior Research Scientist at Google.

Hao Lu is a graduate student at the University of Washington. He is a member of the DUB group.

Summary 

• Hypothesis - The researchers had three hypotheses:
• Gesture Avatar would be slower than Shift on large targets, but faster on small ones.
• Gesture Avatar will be less error-prone than Shift.
• The error rate for Gesture Avatar will not be affected as much by walking as Shift's.
• Method - The participants were to test both systems. Half of them learned Gesture Avatar first, half Shift. The researchers then measured the time from gesture to selection with many variables, such as walking or sitting, number of repeated letters, and the size of the targets. They then compared the results between Gesture Avatar and Shift.
• Results - The results confirmed hypothesis 1: Shift was much faster on large targets, but much slower on small ones. The error rate for Gesture Avatar remained mostly constant, while Shift's went up as target size became smaller. They also confirmed the third hypothesis; Gesture Avatar remained constant between sitting and walking, while Shaft's performance decreased significantly. Only one participant in the study preferred Shift over Gesture Avatar.
• Content -The paper presented the implementation for Gesture Avatar, an API geared towards minimizing errors due to touch-screen based selection. They suggested minor adjustments and modifications to their system that are possible and may be desirable. They developed their product and tested it against Shift to test its strengths and weaknesses. Their results matched their hypotheses and Gesture Avatar had an overall good reception.

 Discussion

 I appreciated the clarity of this paper, and also how relevant its application was to the the general populace. I personally have some troubles (having fat fingers) while selecting small text in a web browser. I have not used Gesture Avatar yet but may pick it up, as it seems others have had good results. I don't particularly like letter-based gestures as a whole, as they can fail at recognizing letters correctly. However, due to the relative simplicity of this one's use, the gesture errors may be minimized more because does not require as much input.