A reduced QWERTY keyboard for mobile text entry

In this paper we describe a specialized keyboard for text entry that maps four rows of a standard keyboard onto the home row, with different characters encoded via modifier keys and multi-tap input. Use of the keyboard also relies on lexicon-based disambiguation. This design has two motivations: limiting physical space requirements and capitalizing on user knowledge of the standard QWERTY keyboard layout. The resulting “stick ” keyboard is between 15 % and 25 % of the size of a standard keyboard. In a preliminary empirical study, users reached half of their normal typing speed using lexicon-based disambiguation (22.5 wpm) and a reasonable but lower speed with multi-tap input (10.4 wpm) with only a few minutes of practice.