Touch Screens That Vibrate
A touch screen that offers tactile feedback could help people type more accurately on PDAs
Source: “Tactile Feedback for Mobile Interactions”
Stephen Brewster et al.
CHI 2007, April 28-May 3, 2007, San Jose, CA
Results: Researchers at the University of Glasgow, Scotland, have found that mobile phones and PDAs whose touch screens vibrate when touched promote better typing and are easier to use than nonvibrating devices. In the lab, subjects made 22 percent fewer typing errors and were able to correct 48 percent more of their errors when they used vibrating PDAs. Those benefits diminished somewhat when subjects were tested on a moving train.
Why it matters: More and more phones are being designed to let users enter numbers and letters using touch screens. But virtual buttons on a flat display simply don’t feel like buttons, and people using them are prone to errors. Some researchers suspect that adding tactile cues–such as vibrations when a screen is touched–will improve the interface.
Methods: To the backs of several PDAs, the researchers attached actuators that caused the gadgets to vibrate when their touch screens were tapped. The vibration was smooth when a subject pressed a button correctly but rougher if the subject made a mistake, such as tapping a button twice. Twelve study participants, who had never used PDAs before, were given poems to type into the devices as accurately and quickly as possible, both in the lab and on a moving train.
Next steps: The group is exploring additional ways of using actuators in mobile devices. For example, actuators at the four corners of a device could denote the progress of a file download: the actuators would vibrate in sequence until the download was complete.