Considerate home notification systems: A user study of acceptability of notifications in a living-room laboratory

Abstract

Recent field experiments on acceptability of notifications in the home showed that people generally want to be informed of urgent messages as soon as possible, whereas non-urgent messages should not be presented at all. A possible way to improve the acceptability of a notification might be to adjust the presentation mode and the timing of notifications to the message content and to the state of the user. For example, acceptability might be improved by considering user activities when selecting the best time to present the message. The relation between acceptability, presentation mode and timing has not been formally studied in a controlled home setting before. This paper presents the results of a user study, in which ten participant couples were asked to engage in everyday home activities, and to subjectively rate factors that were expected to influence acceptability. The study was situated in a living room laboratory in which the user activities and the timing of notifications were controlled. Questionnaire data was evaluated using cluster analysis in order to construct a semantic model that describes the relationship between user, system and environment. The key findings in the present study are: (1) acceptability could be improved by adjusting the level of intrusiveness of the presentation to message urgency: urgent messages should be presented intrusively, medium-urgent messages unobtrusively, and (2) non-urgent messages should be postponed until the message urgency has increased, or skipped if the message urgency never exceeds the predefined presentation threshold.. Surprisingly, the user activities at the time of notification were not found to influence acceptability. These findings have resulted in a model of acceptability of notifications for the design of future home notification systems.

The Role of Modality in Notification Performance

“…The results of the study will help developers to include these modalities, allowing them to create home care technology that is more appropriate, acceptable and effective. This knowledge will also help to expand upon models of interruptibility in the home, such as that developed by Vastenburg, Keyson and Ridder [27]. Their model considers message urgency and user engagement to evaluate notification acceptability, which is very much a step in the required direction.…”

The impact of unwanted multimodal notifications

“…This highlights the importance of a good notification scheduler, able to manage and control notifications of all modalities so that low-priority notifications are not delivered disruptively and that important notifications are delivered in a timely manner in an appropriate modality. This is an active area of research which has already shown how effective a welldesigned notification scheduler can be [3,12,28]. However, more research is needed to guide the design of multimodal notification systems for the home.…”

“…Vastenburg, Keyson & Ridder [28] reported that people did not want to be interrupted for low-urgency information. A notification may be unwanted because the user is engaged in an important or demanding task and does not want to be distracted.…”

Ambient Timer – Unobtrusively Reminding Users of Upcoming Tasks with Ambient Light

“…Vastenburg et al reported their work on the acceptability of notifications in home situations [29]. They found a correlation between user acceptability and intrusiveness and importance of the displayed message.…”