Two methods of text entry using handheld keypads were compared - the conventional multi-press (SMS) method and a novel four-way method. The latter utilizes special keys that can be pressed in one of four directions, allowing one press per character entry. Ten participants took part in one training session and nine experimental sessions, five using the four-way method and five using the Multi-press method. During the nine experimental sessions each participant entered a total of 450 sentences (mean: 30.5 characters per sentence). The four-way method yielded higher speeds throughout all stages of the experiment and increased with practice, indicating that expert users would display a greater advantage when using the four-way method than the advantage shown even in the last sessions. A linear improvement with practice was found for the four-way method, demonstrating that participants were far from reaching asymptotic performance.
