Comparison of Mobile Text Entry Methods

In this preliminary study, we tested a small group of users on their ability to perform common text input tasks using both standard and unfamiliar input devices: the standard QWERTY keyboard, an onscreen QWERTY keyboard on a Pocket PC, a letter recognition system on a Pocket PC, and a T9 text-input system on a cellular phone. We examined user performance, accuracy, and overall preference for the four input methods, and compared these results to the values predicted by Fitts' Law. Our findings suggest that the cognitive effort loads for each device had a strong impact on the amount of time required by users to input text, and that Fitts' Law methods do not accurately account for or predict values including cognitive load or skill transfer.