Spotted: Pinch-to-zoom is a fitts task

 // published on Human Computer Interaction with Mobile Devices and Services-Latest Proceeding Volume // visit site

Exploring pinch and spread gestures on mobile devices
Jessica J. Tran, Shari Trewin, Calvin Swart, Bonnie E. John, John C. Thomas

Pinching and spreading gestures are prevalent in mobile applications today, but these gestures have not yet been studied extensively. We conducted an exploratory study of pinch and spread gestures with seated participants on a phone and a tablet device. We found device orientation did not have a significant effect on gesture performance, most pinch and spread tasks were completed in a single action, and they were executed in 0.9-1.2 seconds. We also report how participants chose to sit with the mobile device, variations in gesture execution method, and the effect of varying target width and gesture size. Our task execution times for different gesture distances and precision levels display a surprisingly good fit to a simple Fitts's Law model.