Disappearing Mobile Devices

Mobile devices are getting smaller all the time. With this comes a growing problem. Peoples hands stay the same size and are too big for people to use the tiny interfaces. In this paper, Tao Ni and Patrick Baudisch look for ways to interface with very small mobile devices. They first decided that a gesture recognition system would work best. To record the gestures, motion scanners, touch scanners and direction scanners were used. Some of the problems that occurred when trying to implement the gesture system were that sometimes a person's finger was too small and caused errors when the sensor no longer detected the person's finger. To compensate for this, the user used their entire hand instead of just a finger to make gestures.

They decided to test the system using two different unistroke input systems, Graffiti and EdgeWrite. The participants in the test were able to use the EdgeWrite system using this interface with much fewer errors than with the Graffiti system. By the end of the study, they had come up with a list of design implications for a disappearing mobile device, including:

• Use the entire hand for input to allow for larger motion amplitude. It reduces error with complex gestures.
• Preferably use unistroke gestures that do not rely on the correct recognition of relative position features. (This is what caused many of the errors for users using Graffiti.)
• Design devices, such that they glance over irregularities and gaps between fingers. However, limit the focal range to prevent motion past lift-off from being recognized as a gesture.

While I thought it was a cool idea, I think it would be very difficult to use. I would struggle to remember the gestures. Also, they have not developed anything to give the user any visual feedback. The user doesn't know if the gesture they made is correct or not. I would try to fix that problem if I were to continue work on this project.