Slide Rule’s interface is entirely speech-based and has no visual representation. Slide Rule displays a solid color on the screen to indicate that it is running, but provides no other visual feedback.
Despite its non-visual interface, Slide Rule lays out objects on the screen spatially using linear lists. Users navigate through lists of items by scanning their fingers down the device surface, and use gestures to interact directly with on-screen objects. For example, rather than finding and tapping a ‘Forward’ button in the Mail application, users forward a message by locating the message with their finger and performing a right-flick gesture. This style of interaction is uncommon in systems designed for blind users, but reduces the need to constantly locate targets on the touch screen.
- S.K. Kane, J.P. Bigham, and J.O. Wobbrock, “Slide rule: making mobile touch screens accessible to blind people using multi-touch interaction techniques,” Proceedings of the 10th international ACM SIGACCESS conference on Computers and accessibility, Halifax, Nova Scotia, Canada: ACM, 2008, pp. 73-80. [Online]. Available: http://faculty.washington.edu/wobbrock/pubs/assets-08.pdf