Physics-based graphical keyboard design

Built upon the Fitts' law and digraph model developed by MacKenzie and colleague [2, 3], we introduce two physics-based methods to graphical keyboard design. One method uses physical simulation of digraph springs and the other uses the Metropolis method. Both methods produced keyboard layouts comparable to or better than existing best designs by manual trial and error methods. We also corrected an error in previous predictions and concluded that the upper bound performance of a graphical keyboard should be at 40 to 44 wpm. The effect of varying key size and the use of multiple space keys are discussed.