Will Input Style Affect Mandarin Short Messages in Mobile Device?: a Wizard of Oz Study

Speech input is a natural text entry method for handheld devices that are used in different contexts. We conducted an experiment to understand effects of input (speaking) style (phrasal vs. sentence input) on Chinese text entry rates and user satisfaction with other two variables: recognition rate (50%, 70% and 90%) and message length (10 vs. 20 characters). Wizard of Oz was applied in the experiment due to lack of a working prototype. The results indicated sentence input was better on text entry rates and preferred by end users rather than phrasal input when recognition rate was high. Recognition rate and message length affected both user performance and satisfaction. Further task analysis on the Mandarin message dictation process indicated that error correction took the most percentage of task completion time, followed by candidate selection and speaking phase. Finally, design guidelines on Mandarin dictation application were discussed.