May 10, 2012 @ 14:30, Room: Ballroom E
Chair: Mike Horn, Northwestern University, USA
Evaluation of Human Tangential Force Input Performance - Paper
Contribution & Benefit: Presents guidelines for UI design based on the tangential force applied by a user. Can assist in developing effective force-based interface.
Abstract » While interacting with mobile devices, users may press against touch screens and also exert tangential force to the display in a sliding manner. We seek to guide UI design based on the tangential force applied by a user to the surface of a hand-held device. A prototype of an interface using tangential force input was implemented utilizing a force sensitive layer and an elastic layer and used for the user experiment. We investigated user controllability to reach and maintain target force levels and considered the effects of hand pose and direction of force input. Our results imply no significant difference in performance when applying force holding the device in one hand and in two hands. We also observed that users have more physical and perceived loads when applying tangential force in the left-right direction compared to the up-down direction. Based on the experimental results, we discuss considerations for user interface applications of tangential-force-based interface.
ACMPocketNavigator: Studying Tactile Navigation Systems In-Situ - Paper
Contribution & Benefit: Provides evidence from a study of a pedestrian navigation system published on the Android Market which shows that vibro-tactile navigation instructions can reduce the traveler's level of distraction.
Abstract » 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.
ACMFunneling and Saltation Effects for Tactile Interaction with Virtual Objects - Paper
Contribution & Benefit: We have newly verified for the first time that funneling and saltation, the two main perceptual tactile illusions exist also on virtual objects without any physical medium.
Abstract » Funneling and saltation are two major illusory feedback techniques for vibration-based tactile feedback. They are often put into practice e.g. to reduce the number of vibrators to be worn on the body and thereby build a less cumbersome feedback device. Recently, these techniques have been found to be applicable to eliciting "out of the body" experiences as well (e.g. through user-held external objects). This paper examines the possibility of applying this phenomenon to interacting with virtual objects. Two usability experiments were run to test the effects of funneling and saltation respectively for perceiving tactile sensation from a virtual object in an augmented reality setting. Experimental results have shown solid evidences for phantom sensations from virtual objects with funneling, but mixed results for saltation.
ACMUsing Shear as a Supplemental Two-Dimensional Input Channel for Rich Touchscreen Interaction - Note
Contribution & Benefit: In this note, we suggest using a largely unutilized touch input dimension: shear (force tangential to a screen's surface). This provides a supplemental analog 2D input channel.
Abstract » Touch input is constrained, typically only providing finger X/Y coordinates. To access and switch between different functions, valuable screen real estate must be allocated to buttons and menus, or users must perform special actions, such as touch-and-hold, double tap, or multi-finger chords. Even still, this only adds a few bits of additional information, leaving touch interaction unwieldy for many tasks. In this work, we suggest using a largely unutilized touch input dimension: shear (force tangential to a screen's surface). Similar to pressure, shear can be used in concert with conventional finger positional input. However, unlike pressure, shear provides a rich, analog 2D input space, which has many powerful uses. We put forward five classes of advanced interaction that considerably expands the envelope of interaction possible on touchscreens.
ACMGyroTab: A Handheld Device that Provides Reactive Torque Feedback - Note
Contribution & Benefit: Presents GyroTab, a flat handheld system that utilizes the gyro effect to provide torque feedback on mobile devices. The feedback can be used to convey the feeling of weight or inertia.
Abstract » Haptic devices that provide robust and realistic force feedback are generally grounded to counterweight the applied force, prohibiting their use in mobile devices. Many ungrounded force-feedback devices rely on the gyro effect to produce torques on the human body, but their active control systems render them extremely bulky for implementation in small mobile devices. We present GyroTab, a relatively flat handheld system that utilizes the gyro effect to provide torque feedback. GyroTab relies on the user to produce an input torque and provides feedback by opposing that torque, making its feedback reactive to the user�s motion. We describe the implementation of GyroTab, discuss the kinds of feedback it generates, and explore some of the psychophysical results we obtained from a study with the device.
ACM