We propose a new interface concept; Proprioceptive Menu with Tactons, an eyes- and ears-free menu in a proprioceptive space that uses a set of Tactons to describe its menu items. While previous proprioceptive menus utilized vibrotactile feedback only to express the boundary between menu items, we spot an unexplored possibility that distinct vibrotactile stimuli, Tactons, can be used to describe the status of each menu item. As an instance of this concept, we present WristMenu with Tactons, an eyes- and ears-free menu using a one-dimensional proprioceptive space of the axial wrist rotation. Users can grasp an overview of each menu item’s status through Tactons delivered on their wrist skin and eventually decide to select the desired item. Our evaluation study showed that users could find a target item among five candidates and recognize its status in 5 seconds on average at the accuracies of 93% and 86% in seated and walking conditions, respectively. Through our evaluation, we could confirm the feasibility of the proposed concept.

Smartwatches are a convenient substitute for smartphones in hand-busy situations, but there is limited interactivity to one-handed use of wrist-worn devices. In this paper, we propose WristDial, a one-handed integer input technique which uses quantization of the angular distance of the wrist rotation with nonvisual feedback. Using tactile feedback, we present four techniques based on counting of tactile stimuli. With one of them, 94.44% average accuracy and 2.81 s average completion time were acquired in the task of entering a number from the range 1 to 10. We also evaluate the quantitative performance of the combination of interruptible speech and non-speech auditory feedback. Our results show that when speech feedback exists, adding a continuous change of pitch or clicking sound at the boundaries does not have a significant effect on the performance. Using only speech feedback, 95.47% accuracy and 1.45 s completion time were acquired.

Promisingly, driving is adapting to a Voice User Interface (VUI) that lets drivers utilize diverse applications with little effort. However, the VUI has innate usability issues, such as a turn-taking problem, a short-term memory workload, inefficient controls, and difficulty correcting errors. To overcome these weaknesses, we explored supplementing the VUI with tactile interaction. As an early result, we present the Voice+Tactile interactions that augment the VUI via multi-touch inputs and high-resolution tactile outputs. We designed various Voice+Tactile interactions to support different VUI interaction stages and derived four Voice+Tactile interaction themes: Status Feedback, Input Adjustment, Output Control, and Finger Feedforward. A user study showed that the Voice+Tactile interactions improved the VUI efficiency and its user experiences without incurring significant additional distraction overhead on driving. We hope these early results open new research questions to improve in-vehicle VUI with a tactile channel.

We explored new interaction scenarios that can be realized when a touchpad outputs fast and high-resolution spatio-temporal tactile patterns to the touch-sensitive skin on the fingertips of a user. We first constructed a special tactile multi-touch touchpad called PinPad, which was capable of outputting fast and high-resolution tactile patterns using a 40 x 25 array of actuated pins. We then developed various interaction scenarios that could be realized using the prototype: 1) Tactile Target, 2) Guide and Constraint, 3) Multi-finger Output, and 4) Dynamic Partition. To evaluate the PinPad scenarios, we implemented demo applications, and conducted interviews with users to collect feedback about their experiences with PinPad and the PinPad scenarios. The participants confirmed the effectiveness of spatio-temporal outputs of PinPad in the scenarios. In particular, they provided diverse feedback regarding the unique tactile experiences of the fast and high-resolution outputs of PinPad.