Abstract
Notification system （NS） is a system which provides extra information when users are performing their tasks. In the past, the researches of notification systems mainly emphasize the objective factors （e.g., display types of interface） but rarely the subjective factors （e.g., human emotions, user’s preference）. This study investigates the effects of emotional factors in notification systems on user’s performance （including interrupting effects, lag time and working performance）. The lag time means the interruption lag and the resumption lag. The interruption lag is the duration of preparation that the user resumes a task after interruption. The resumption lag is the time between leaving the interrupting events and beginning the primary task. It does not necessarily have the interruption lag when the interruption occurs, but the resumption lag will always exist in switching among tasks （Rogers & Monsell, 1995; Allport & Wylie, 2000）. This study explores if the emotional factors in notification systems can effectively shorten the time of working and resumption lag. This study also investigates if there will be a difference about the user’s experience in notification systems with or without the emotional manipulation. The independent variables of this study were the different emotional manipulation and the designs with or without the interruption lag. The dependent variables of this study were the change of the emotional state, the anxious state, the working performance, the resumption lag, and the user’s experience. Significant effects were not found on subject’s score of primary tasks and the speed performing the primary tasks under the positive affect condition, but there was a significant difference in the time of the resumption lag. When the emotional state was more positive, the subjects could resume to the primary tasks faster. In other words, the positive emotions could effectively speed up the recovery to the primary tasks. Besides, there was a reverse relation between the resumption lag and the designs with or without interruption lag. That is, under the situation of offering interruption lag, the subjects would spend less time on the resumption lag. These results indicated that emotions had good effects on switching among tasks, and indirectly confirmed that emotions could improve the working performance in notification systems. According to the results of this study, we provided some directions and design suggestions for future researches.