Seven-Segment Input 7SI: New Stylus-Based Text Entry Method

This paper presents seven-segment input (7SI) as a new text entry method for handheld devices, designed to provide high accuracy through goal-crossing that enables writing even in an unstable environment "on the move". A traditional seven- segment layout is used as a unistroke character input. The 7SI users enter character by crossing subset of seven segments that configures desired character. Thus, gesture recognition does not depend on pattern recognition, but only on the subset of seven segments that is crossed. For assuring high efficiency of entering, a circle in centre of each square of seven-segment layout is added as a shortcut for the characters composed in part by a circle. In order to compute 7SI speed, we have conducted a theoretical evaluation based on Fitts' Law. This study has shown that 7SI entry speed will be 27.49 words per minute.