TYPEHEX keyboard: A virtual keyboard for faster typing in Smartphone

We present a soft keyboard layout and a novel text entry system for smart phones. The major problem In designing a soft keyboard is to fit a large number of buttons within a very tiny touchscreen area. This often leads towards user discomfort and typing mistakes. Our proposed layout, TYPEHEX keyboard, presents full text entry facilities with minimum required finger movement. This name implies our vision towards achieving faster typing speed with less error occurrence using hexagonal buttons. While comparing with soft QWERTY layout, which contains 27 buttons, our proposed keyboard has only 10 functional buttons. The main 5 buttons are given hexagonal shape. It allows us to place 7 characters in a single button (1 in the center and other 6 are placed in six remaining corners of the hexagon). During placing each letter (a-z), we considered letter-frequency data, bigrams and trigrams in order to ensure that frequently used characters, character pairs and character trios are placed as close as possible. We evaluate our design by combining the movement time model which is an application of Fitts' law with the linguistic model. The calculated word per minute (wpm) values for both index finger and thumb shows that our design approach gives improved wpm values than soft QWERTY and T9 input method.