Tlk or txt? Using voice input for SMS composition
This paper reports a series of investigations, which aim to test the appropriateness of voice recognition as an interaction method for mobile phone use. First, a KLM model was used in order to compare the speed of using voice recognition against using multi-tap and predictive text (the two most common methods of text entry) to interact with the phone menus and compose a text message. The results showed that speech is faster than the other two methods and that a combination of input methods provides the quickest task completion times. The first experiment used a controlled message creation task to validate the KLM predictions. This experiment also confirmed that the result was not due to a speed/ accuracy trade off and that participants preferred to use the combination of input methods rather than a single method for menu interaction and text composition. The second experiment investigated the effect of limited visual feedback (when walking down the road or driving a car for example) on interaction, providing further evidence in support of speech as a useful input method. These experiments not only indicate the usefulness of voice in SMS input but also that users could also be satisfied with voice input in hands-busy, eyes-busy situations. © Springer-Verlag London Limited 2007.