Paper Reading #24

Gesture avatar: a technique for operating mobile user interfaces using gestures

Authors:	Hao Lü	University of Washington, Seattle, Washington, USA
	Yang Li	Google Research, Mountain View, California, USA

Proceeding  

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

Summary

• Hypothesis - The researchers believed that their system can be used to easily select small objects on a touch screen better than a previous system called Shift.
• Methods - In order to compare the usability of the Gesture Avatar to Shift in a non-biased way, 20 participants were asked to try each using different sized targets, different number of targets, and testing while either walking or sitting. 10 participants used the Gesture Avatar first, while the other 10 used Shift first. 
• Content - The point in this research is to resolve the "fat finger" and occlusion problems with touch gestures. The fat finger problem is the fact that a finger may be significantly larger than the object to be selected. The occlusion problem states that the user can not specifically see what they are selecting because the finger occludes the screen while interacting with it. Gesture Avatar works by drawing a letter to select a link on a page. If the link's first letter is the letter drawn, it is highlighted. To select the link, the user taps on the bounding box of the gesture they created. If they want to select another link that satisfies the letter, the user drags outside the bounding box to go to the next link. To undo the gesture, the user taps outside the bounding box.
• Results - GA was faster at selecting larger items, but slower at smaller items compared to Shift. GA had the upper hand to shift when walking was involved since walking did not effect the error rate for GA, while shift had a much higher error rate. Because of this, the majority of the participants preferred the Gesture Avatar.

Discussion
This is a pretty clever way of solving the fat finger and occlusion problems. However, I believe most of the issues this solves for web browsing have mostly been partially solved by having mobile versions of pages. Also, I'm not convinced that this is faster than simply zooming into the page to make the links larger. For future work, this application could be integrated into android as an option.