Fast text-entry on miniature mobile devices

Abstract As mobile messaging devices are becoming smaller, for example wristwatches with Internet connectivity, there is less space for keys. Researchers have,experimented,with,3-key text input,devices,and come,up with designs allowing,text to be entered with as little as 4.23 keystrokes per character, but the strategies are hard to use. This paper demonstrates a dictionary-enhanced technique, which allows text to be entered using 2.16 keystroke per character. Four approaches,are investigated ó a ring-based method, a two-level tree-based method, a multi-tap method,and a one-stroke method. Experiments,are used to evaluate,the usability of the approaches,and the results conrm,that there is a trade-off between,usability and,number,of keystrokes per characters. The results show,that the multi-ring approach,requires less concentration,from,the user than previous strategies while text is entered with just 3.2 keystrokes per character. 1 Mobile text entry Asynchronous,messaging,(SMS) using mobile,devices has become,an important means,of written communication,in Europe and is also popular,in America,and Asia. Physical limitations and interaction controls