UIST2015: Touch Input

Biometric Touch Sensing: Seamlessly Augmenting Each Touch with Continuous Authentication

http://dl.acm.org/citation.cfm?id=2807458

Current touch devices separate user authentication from regular interaction, for example by displaying modal login screens before device usage or prompting for in-app passwords, which interrupts the interaction flow. We propose biometric touch sensing, a new approach to representing touch events that enables commodity devices to seamlessly integrate authentication into interaction: From each touch, the touchscreen senses the 2D input coordinates and at the same time obtains biometric features that identify the user. Our approach makes authentication during interaction transparent to the user, yet ensures secure interaction at all times. To implement this on today’s devices, our watch prototype Bioamp senses the impedance profile of the user’s wrist and modulates a signal onto the user’s body through skin using a periodic electric signal. This signal affects the capacitive values touchscreens measure upon touch, allowing devices to identify users on each touch. We integrate our approach into Windows 8 and discuss and demonstrate it in the context of various use cases, including access permissions and protecting private screen contents on personal and shared devices. 

-user authentication

-continuous authentication

-detect people based on shoes

-data transfer to touchscreen

-conversation with Atmel

-go through body -> can do with ankle

Push-Push: A Drag-like Operation Overlapped with a Page Transition Operation on Touch Interfaces

http://dl.acm.org/citation.cfm?id=2807457

A page transition operation on touch interfaces is a common and frequent subtask when one conducts a drag-like operation such as selecting text and dragging an icon. Traditional page transition gestures such as scrolling and flicking gestures, however, cannot be conducted while conducting the drag-like operation since they have a confliction. We proposed Push-Push that is a new drag-like operation not in conflict with page transition operations. Thus, page transition operations could be conducted while performing Push-Push. To design Push-Push, we utilized the hover and pressed states as additional input states of touch interfaces. The results from two experiments showed that Push-Push has an advantage on increasing performance and qualitative opinions of users while reducing the subjective overload.

Out > hover > touch > press

Exploring and Understanding Unintended Touch during Direct Pen Interaction

The user experience on tablets that support both touch and styli is less than ideal, due in large part to the problem of unintended touch or palm rejection. Devices are often unable to distinguish between intended touch (i.e., interaction on the screen intended for action) and unintended touch (i.e., incidental interaction from the palm, forearm, or fingers). This often results in stray ink strokes and accidental navigation, frustrating users. We present a data collection experiment where participants performed inking tasks, and where natural tablet and stylus behaviors were observed and analyzed from both digitizer and behavioral perspectives. An analysis and comparison of novel and existing unintended touch algorithms revealed that the use of stylus information can greatly reduce unintended touch. Our analysis also revealed many natural stylus behaviors that influence unintended touch, underscoring the importance of application and ecosystem demands, and providing many avenues for future research and technological advancement.

-distinguish intentional / unintentional touch
-palm rejection - skin input variations, hand posture, method of moving stylus
-right/left handed users behave differently
-importance of pre-touch information and continuous stylus location

Pin-and-Cross: A Unimanual Multitouch Technique Combining Static Touches with Crossing Selection

http://dl.acm.org/citation.cfm?id=2807444

We define, explore, and demonstrate a new multitouch interaction space called “pin-and-cross.” It combines one or more static touches (“pins”) with another touch to cross a radial target, all performed with one hand. A formative study reveals pin-and-cross kinematic characteristics and evaluates fundamental performance and preference for target angles. These results are used to form design guidelines and recognition heuristics for pin-and-cross menus invoked with one and two pin fingers on first touch or after a drag. These guidelines are used to implement different pin-and-cross techniques. A controlled experiment compares a one finger pin-and-cross contextual menu to a Marking Menu and partial Pie Menu: pin-and-cross is just as accurate and 27% faster when invoked on a draggable object. A photo app demonstrates more pin-and-cross variations for extending two-finger scrolling, selecting modes while drawing, constraining two-finger transformations, and combining pin-and-cross with a Marking Menu.

Disclaimer: The opinions expressed here are my own, and do not reflect those of my employer. -Fumi Yamazaki