Abstract
This research aimed to investigate and explore expert user interface design principle in adaptive user interface of in-vehicle full voiced-based interface. The voice-based interaction interface with expert convenience was developed step by step through three stages of experiments. The voice-based interface called Talking Car novice interface has been designed before. By conducting those driving simulation experiments, number of characters in Chinese the expert could tolerate of Talking Car expert interface would be found and ensure there are sufficient users’ operation efficiency and traffic safety.There were sixteen participants who had car driving licenses and were novice user of in-vehicle full voiced-based interface. They would be trained into expert users by going through the experiments. At first, the novice participants used Talking Car novice interface to carry out the experiment, then the number of characters the advanced-novice users could tolerate of Talking Car would be found. According to the result, the length of speech by Talking Car would be adjusted to fulfill advanced-novice users’ requirements, and then it change into Talking Car advanced-novice interface. Then, the Talking Car expert interface would be developed after second stage experiment (advanced-novice user using advanced-novice interface). After that, those participants would carry out the third stage experiment to verify the usability as well as the implications on operation efficiency and traffic safety by using Talking Car expert interface. In driving simulated experiments, a camera was set to capture the subject’s operations, reaction time of the brakes when “STOP!!” message showed on the display and the task completion time. After the experiment finished, subjects would be asked to complete three questionnaires, included NASA-TLX, subjective and impatient-degree questionnaire, to evaluation subjects’ workload, satisfaction and the degree of impatient of system speeches.After three stage experiments, the results suggested the suitable sentence length of each interface. According to the experiment result, we could also define that novice interface sentence would be changed into advanced speech sentence when it has been interrupted for 6 times, and advanced-novice interface would be changed into expert interface sentence when it has been interrupted for 5 times. In addition, the sentence of expert interface resulted in lowest degree of impatient, required less operation time and mental workload than that of other interfaces. Therefore, drivers not only feel more convenience but also have a safer driving condition when they are controlling the Talking Car Expert Mode.