Dr.-Ing. Anja Faulhaber

In this paper, we present a concept for an assistance system for public transport passengers currently being developed for Kassel, Germany, and its surrounding area. The assistance system aims at increasing the attractiveness of local public transport by reducing barriers to use, thus promoting sustainable travel behavior. Three main barriers were identified: crowded vehicles, missed connections, and inconveniences in the transportation of shopping bags and luggage. To tackle these issues, three assistance system services were conceptualized: the occupancy rate informing passengers about the occupancy level of vehicles, the transfer connection monitor and secure system giving passengers the option to communicate transfer connection requests, and the delivery service allowing the use of public transport while shopping without the need to transport purchased goods. The three services are presented in detail along with the user interfaces they will be integrated into. Moreover, for the further implementation of the assistance system, a user requirement analysis is outlined. We finally give an overview and outlook regarding the implementation and evaluation of the concept in laboratory studies and a one-year field study.

Smart glasses are increasingly commercialized and may replace or at least complement smartphones someday. Common smartphone features, such as notifications, should then also be available for smart glasses. However, notifications are of disruptive character given that even unimportant notifications frequently interrupt users performing a primary task. This often leads to distractions and performance degradation. Thus, we propose a concept for displaying notifications in the peripheral field of view of smart glasses and with different visualizations depending on the priority of the notification. We developed three icon-based notifications representing increasing priority: a transparent green icon continuously becoming more opaque (low priority), a yellow icon moving up and down (medium priority), and a red and yellow flashing icon (high priority). To evaluate the concept, we conducted a study with 24 participants who performed a primary task and should react to notifications at the same time using the Nreal Light smart glasses. The results showed that reaction times for the low-priority notification were significantly higher and it was ranked as the least distracting. The medium- and high-priority notifications did not show a clear difference in noticeability, distraction, or workload. We discuss implications of our results for the perception and visualization of notifications in the peripheral field of view of smart glasses and, more generally, for augmented reality applications.

We propose a concept for displaying notifications in the peripheral field of view of smart glasses aiming to achieve a balance between perception and distraction depending on the priority of the notification. We designed three different visualizations for notifications of low, medium, and high priority. To evaluate this concept, we conducted a study with 24 participants who reacted to the notifications while performing a primary task. Reaction times for the low-priority notification were significantly higher. The medium- and high-priority notifications did not show a clear difference.

Augmented Reality (AR) glasses may be used in diverse mobile and multitasking contexts, for example, while walking. In such contexts, it is particularly important to display information without obscuring essential areas of central vision. Information can, thus, be presented to the peripheral vision. The objective of the present study was to investigate how peripheral visual cues should be displayed in AR to achieve efficient perception during walking. We conducted a pilot study and tested three different versions of directional cues presented while walking or standing still: simply popping up, moving towards the indicated direction, or changing color. The results indicated that the perception of peripheral cues in AR is generally less efficient while walking than standing still. Within the walking condition, the color-changing cue was perceived best.

The present study aimed to investigate whether explanations increase trust in an assistance system. Moreover, we wanted to take the role of the individual propensity to trust in technology into account. We conducted an empirical study in a virtual reality environment where 40 participants interacted with a specific assistance system for public transport users. The study was in a 2x2 mixed design with the within-subject factor assistance system feature (trip planner and connection request) and the between-subject factor explanation (with or without). We measured trust as explicit trust via a questionnaire and as implicit trust via an operationalization of the participants’ behavior. The results showed that trust propensity predicted explicit trust, and explanations increased explicit trust significantly. This was not the case for implicit trust, though, suggesting that explicit and implicit trust do not necessarily coincide. In conclusion, our results complement the literature on explainable artificial intelligence and trust in automation and provide topics for future research regarding the effect of explanations on trust in assistance systems or other technologies.