Florian Heller

FabriTouch: exploring flexible touch input on textiles

Touch-sensitive fabrics let users operate wearable devices unobtrusively and with rich input gestures similar to those on modern smartphones and tablets. While hardware prototypes exist in the DIY crafting community, HCI designers and researchers have little data about how well these devices actually work in realistic situations. FabriTouch is the first flexible touch-sensitive fabric that provides such scientifically validated information. We show that placing a FabriTouch pad onto clothing and the body instead of a rigid support surface significantly reduces input speed but still allows for basic gestures. We also show the impact of sitting, standing, and walking on horizontal and vertical swipe gesture performance in a menu navigation task. Finally, we provide the details necessary to replicate our FabriTouch pad, to enable both the DIY crafting community and HCI researchers and designers to build on our work.

PowerSocket: towards on-outlet power consumption visualization

Power consumption is measured in W and Wh, but what do these units mean? Water consumption can easily be understood, as we all know what a liter of water looks like. Common power meters, however, rely on the physical units or their translation to costs as display. We classified existing displays and ambient visualizations in a taxonomy that focuses on the characteristics of power consumption displays. We adapted representatives of the different categories of displays to an on-outlet display and compared these using a combination of soft- and hardware prototyping. Results indicate that ambient visualizations make it easier to understand power consumption.

Multi-user interaction in virtual audio spaces

Audio guides are a common way to provide museum visitors with an opportunity for personalized, self-paced information retrieval. However, this personalization conflicts with some of the reasons many people go to museums, i.e., to socialize, to be with friends, and to discuss the exhibit as they experience it [1]. We developed an interactive museum experience based on audio augmented reality that lets the visitor interact with a virtual spatial audio soundscape. In this paper, we present some new interaction metaphors we use in the design of this audio space, as well as some techniques to generate a group experience within audio spaces.

Simplifying orientation measurement for mobile audio augmented reality applications

Audio augmented reality systems overlay the physical world with a virtual audio space. Todays smartphones provide enough processing power to create the impression of virtual sound sources being located in the real world. To achieve this, information about the users location and orientation is necessary which requires additional hardware. In a real-world installation, however, we observed that instead of turning their head to localize sounds, users tend to turn their entire body. Therefore, we suggest to simply measure orientation of the users body - or even just the mobile device she is holding - to generate the spatial audio. To verify this approach, we present two studies: Our first study in examines the users head, body, and mobile device orientation when moving through an audio augmented reality system in a lab setting. Our second study analyzes the user experience in a real-world installation when using head, body, or device orientation to control the audio spatialization. We found that when navigating close to sound sources head tracking is necessary, but that it can potentially be replaced by device tracking in larger or more explorative usage scenarios. These findings help reduce the technical complexity of mobile audio augmented reality systems (MAARS), and enable their wider dissemination as mobile software-only apps.

Physical prototyping of an on-outlet power-consumption display

Sustainability in (Inter)Action provides a forum for innovative thought, design, and research in the area of interaction design and environmental sustainability. The column explores how HCI can contribute to the complex and interdisciplinary efforts to address sustainability challenges. Elaine M. Huang, Editor

Grabrics: A Foldable Two-Dimensional Textile Input Controller

Textile interfaces can be ubiquitously integrated into the fabrics that already surround us. So far, existing interfaces transfer concepts, such as buttons and sliders, to the textile domain without leveraging the affordances and qualities of fabric. This paper presents Grabrics, a two-dimensional textile sensor that is manipulated by grabbing a fold and moving it between your fingers. Grabrics can be integrated invisibly into everyday clothing or into textile objects, like a living room sofa, while minimizing accidental activation. We describe the construction and the fold-based interaction technique of our Grabrics sensor. A preliminary study shows that Grabrics can be folded and manipulated from any arbitrary position, and it can detect 2D stroke gestures.

Pinstripe: eyes-free continuous input anywhere on interactive clothing

We present Pinstripe, a textile user interface element for eyes-free, continuous value input on smart garments that uses pinching and rolling a piece of cloth between your fingers. Input granularity can be controlled by the amount of cloth pinched. Pinstripe input elements are invisible, and can be included across large areas of a garment. Pinstripe thus addresses several problems previously identified in the placement and operation of textile UI elements on smart clothing.

Grabbing at an angle: menu selection for fabric interfaces

This paper investigates the pinch angle as a menu selection technique for two-dimensional foldable textile controllers. Based on the principles of marking menus, the selection of a menu item is performed by grabbing a fold at a specific angle, while changing value is performed by rolling the fold between the fingers. In a first experiment we determined an upper bound for the number of different angles users can reliably grab into a piece of fabric on their forearm. Our results show that users can, without looking at it, reliably grab fabric on their forearm with an average accuracy between 30° and 45°, which would provide up to six different menu options selectable with the initial pinch. In a second experiment, we show that our textile sensor, Grabrics, can detect fold angles at 45° spacing with up to 85% accuracy. Our studies also found that user performance and workload are independent of the fabric types that were tested.

AudioScope: Smartphones as Directional Microphones in Mobile Audio Augmented Reality Systems

Mobile audio augmented reality systems (MAARS) provide a new and engaging modality to present information or to create playful experiences. Using special filters, spatial audio rendering creates the impression that the sound of a virtual source emanates from a certain position in the physical space. So far, most of the implementations of such systems rely on head tracking to create a realistic effect, which requires additional hardware. Recent results indicate that the built-in sensors of a smartphone can be used as source for orientation measurement, reducing deployment to a simple app download. AudioScope presents an alternative interaction technique to create such an experience, using the metaphor of pointing a directional microphone at the environment. In an experiment with 20 users, we compared the time to locate a proximate audio source and the perceived presence in the virtual environment. Results show that there is no significant difference between head-orientation measurement and AudioScope regarding accuracy and perceived presence. This means that MAARS, such as audio guides for museums, do not require special hardware but can run on the visitors smartphones with standard headphones.

Maps and Location: Acceptance of Modern Interaction Techniques for Audio Guides

Traditional audio guides in museums and similar spaces typically require the visitor to locate a track number at each exhibit and enter it on a keypad. These guides, however, provide no information on the amount of content available. Current mobile devices provide rich output capabilities, and indoor location tracking technology can simplify the selection of content in modern audio guides. In this paper, we compare the keypad-based interface to a map-based interface with and without automatic localization. Through a field study in a local museum with 84 participants, we found that the usability of all versions is rated high, with the keypad interface coming out ahead. Nevertheless, visitors favored the overview of the map and thumbnails to find the right exhibit, while numbers were considered helpful indicators in the real world. Those who used the self-localizing guide preferred it over manually adjusting the map.