Eyes-Free Output Using a Force Feedback Touch Surface.

(a research project with Anne Roudaut, who is the primary investigator & first author)

Behind gesture output stands the idea to use spatial gestures not only for input but also for output. Analogous to gesture input, gesture output moves the user’s finger in a gesture, which the user then recognizes. A motion path forming a “5”, for example, may inform the user about five unread messages; a heart-shaped path may serve as a message from a close friend.


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We have conducted three user studies, in which participants recognized marking output with 97% accuracy, Graffiti digits with 98.8%, compound pairs of Graffiti digits with 90.5%, and Graffiti letters with 93.4%. Participants previously unfamiliar with Graffiti correctly identified 96.2% of digits and 76.4% of letters, suggesting that properly designed gesture output is guessable. After the experiment, the same participants were able to enter 100% of Graffiti digits by heart and 92.2% of Graffiti letters. This suggests that gesture output teaches gesture input as a side effect.

“Touchy talkie” scenario (a) he sends a heart and (b) when she touches her device, the message is played back by moving her finger along the same heart.

Gesture Output is a research project by Anne Roudaut, Pedro Lopes, Christoph Sterz, Andreas Rau and Patrick Baudisch at the Human Computer Interaction Lab at Hasso Plattner Institute.


Video (51s version)

Video (2m20s version)


Roudaut, A., Sterz, C., Rau, A., Plauth, M., Lopes, P. and Baudisch, P. Gesture Output: Eyes-Free Output Using a Force Feedback Touch Surface. In Proceedings of CHI 2013.


All images Copyright © 2013 Hasso-Plattner-Institut.

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In collaboration with Samsung