Touch gestures become steadily more important with the ongoing success of touch screen devices. Compared to traditional user interfaces, gestures have the potential to lower cognitive load and the need for visual attention. However, nowadays gestures are defined by designers and developers and it is questionable if these meet all user requirements. In this paper, we present two exploratory studies that investigate how users would use unistroke touch gestures for shortcut access to a mobile phone's key functionalities. We study the functions that users want to access, the preferred activators for gesture execution, and the shapes of the user-invented gestures. We found that most gestures trigger applications, letter-shaped gestures are preferred, and the gestures should be accessible from the lock screen, the wallpaper, and the notification bar. We conclude with a coherent, unambiguous set of gestures for the 20 most frequently accessed functions, which can inform the design of future gesture-controlled applications.

Diary studies are often applied in HCI research to collect qualitative user impressions. Unfortunately, the period between creation of a diary entry and the later reflection can be too long, which leads to a limited currentness and contextuality. This eventually results in incomplete or misinterpreted data. In this paper we present Storyteller, a mobile application that allows a quick creation of diary entries and encourages users to reflect on these in-situ through a storytelling approach. We argue that this can lead to more accurate and substantial qualitative insights.

Travelers sometimes need to reach a destination in a given amount of time. However, today's navigation systems try to route users to the destination as fast as possible. In this paper, we present the concept of time-based pedestrian navigation. We use a map on a smartphone that highlights streets depending on whether they will lead to a destination in time. Our map also allows the users to choose between route alternatives during the walk.

In this paper, we report about a large-scale in-situ study of tactile feedback for pedestrian navigation systems. Recent advances in smartphone technology have enabled a number of interaction techniques for smartphone that use tactile feedback to deliver navigation information. The aim is to enable eyes-free usage and avoid distracting the user from the environment. Field studies where participants had to fulfill given navigation tasks, have found these techniques to be efficient and beneficial in terms of distraction. But it is not yet clear whether these findings will replicate in in-situ usage. We, therefore, developed a Google Maps-like navigation application that incorporates interaction techniques proposed in previous work. The application was published for free on the Android Market and so people were able to use it as a navigation system in their everyday life. The data collected through anonymous monitoring suggests that tactile feedback is successfully adopted in one third of all trips and has positive effects on the user's level of distraction.

Going on excursions to explore unfamiliar environments by bike is a popular activity in many places in this world. To investigate the nature of exploratory bicycle trips, we studied tourists on their excursions on a famous vacation island. We found that existing navigation systems are either not helpful or discourage exploration. We therefore propose Tacticycle, a conceptual prototype of a user interface for a bicycle navigation system. Relying on a minimal set of navigation cues, it helps staying oriented while supporting spontaneous navigation and exploration at the same time. In cooperation with a bike rental, we rented the Tacticycle prototype to tourists who took it on their actual excursions. The results show that they always felt oriented and encouraged to playfully explore the island, providing a rich, yet relaxed travel experience. On the basis of these findings, we argue that exploratory trips can be very well supported by providing minimal navigation cues only.

One of the bottlenecks in today's pedestrian navigation system is to communicate the navigation instructions in an efficient but non-distracting way. Previous work has suggested tactile feedback as solution, but it is not yet clear how it should be integrated into handheld navigation systems to improve efficiency and reduce distraction. In this paper we investigate augmenting and replacing a state of the art pedestrian navigation system with tactile navigation instructions. In a field study in a lively city centre 21 participants had to reach given destinations by the means of tactile, visual or multimodal navigation instructions. In the tactile and multimodal conditions, the handheld device created vibration patterns indicating the direction of the next waypoint. Like a sixth sense it constantly gave the user an idea of how the route continues. The results provide evidence that combining both modalities leads to more efficient navigation performance while using tactile feedback only reduces the user's distraction.

This article reports on a preliminary study, which investigates if vibration and speech feedback can be used in order to make a digital map on a touch screen device more accessible. We test if vibration feedback combined with speech, triggered as the finger moves over relevant map objects, works to make sense of the map content. The study results indicate that it is indeed possible to get a basic overview of the map layout even if a person does not have access to the visual presentation. In the conclusions the interaction problems are indentified and suggestions for future improvements are given.

Pedestrian navigation systems are becoming popular but the currently dominant audio-visual interaction can have drawbacks. Tactile feedback is studied as a solution, but currently only available as research prototypes. With the PocketNavigator we propose a demonstrator that adds tactile feedback to a simple but robust map-based navigation system that runs on any Android Smartphone. Users can leave the device in the pocket, while being guided non-visually through vibration cues. Like a compass we "point at" the next waypoint by encoding its direction and distance in vibration patterns. As an advantage over previous approaches it allows giving continuous feedback instead of isolated turning instructions and it can be realized without custom-built tactile displays. Preliminary results from a field study show that pedestrian can effectively use this Tactile Compass to reach a destination without turn-by-turn instructions. Integrated into the PocketNavigator we can now deploy it at the Android Market to evaluate the Tactile Compass with a wide range of users.

Cycling is a common leisure time sports in touristic regions. For us it was the question how tourists actually find their paths in the area and what kind of navigation aids might be helpful to them. In a requirements study on a touristic island we learned that tourists rather explore the environment spontaneously than efficiently navigating from on place to another such as the beach or the light house, and just cycle on without much map or navigation aid. While exploring the area, the cyclists however, sometimes lose their orientation which they compensate for by accepting detours. We designed and developed an orientation aid, Tacticycle that does not influence the cycling experience but improve the orientation and awareness of the overall direction. In order to ensure the cyclists' safety two vibrotactile actuators are used to indicate directions and announce the presence of interesting places. In two field studies we showed that despite the accuracy of the indicated direction being rather coarse, the tactile user interface allows cyclists to reach a presented destination easily. The visitor of the demo can experience a virtual cycling tour supported by the Tacticycle demonstrator.

In many applications today user interaction is moving away from mouse and pens and is becoming pervasive and much more physical and tangible. New emerging interaction technologies allow developing and experimenting with new interaction methods on the long way to providing intuitive human computer interaction. In this paper, we aim at recognizing gestures to interact with an application and present the design and evaluation of our sensor-based gesture recognition. As input device we employ the Wii-controller (Wiimote) which recently gained much attention world wide. We use the Wiimote's acceleration sensor independent of the gaming console for gesture recognition. The system allows the training of arbitrary gestures by users which can then be recalled for interacting with systems like photo browsing on a home TV. The developed library exploits Wii-sensor data and employs a hidden Markov model for training and recognizing user-chosen gestures. Our evaluation shows that we can already recognize gestures with a small number of training samples. In addition to the gesture recognition we also present our experiences with the Wii-controller and the implementation of the gesture recognition. The system forms the basis for our ongoing work on multimodal intuitive media browsing and are available to other researchers in the field.