www.dgp.toronto.edu Current user interface widgets typically assume that the input device can only provide x-y position and binary button press information. Other inputs such as the continuous pressure data provided by styluses on tablets are rarely used. We explore the design space of using the continuous pressure sensing capabilities of styluses to operate multi-state widgets. We present the results of a controlled experiment that investigates human ability to perform discrete target selection tasks by varying a stylus ’ pressure, with full or partial visual feedback. The experiment also considers different techniques for confirming selection once the target is acquired. Based on the experimental results, we discuss implications for the design of pressure sensitive widgets. A taxonomy of pressure widgets is presented, along with a set of initial concept sketches of various pressure widget designs.

EdgeWrite is a new unistroke text entry method for handheld devices designed to provide high accuracy and stability of motion for people with motor impairments. It is also effective for able-bodied people. An EdgeWrite user makes characters by traversing the edges and diagonals of a square hole imposed over the usual text input area. Gesture recognition is accomplished not through pattern recognition but through the sequence of comers that are hit. This means that the full stroke path is unimportant and the recognition is highly deterministic, enabling better accuracy than other gestural alphabets such as Graffiti. In our evaluation of able-bodied users, subjects with no prior experience were 18% more accurate during text entry with EdgeWrite than with Graffiti (p<.05), with no significant difference in speed. In our user studies with 4 subjects with motor impairments, all of them had dramatically better accuracy with EdgeWrite than Graffiti.

We describe input devices and two-handed interaction techniques to support map navigation tasks. We discuss several design variations and user testing of two-handed navigation techniques, including puck and stylus input on a Wacom tablet, as well as a novel design incorporating a touchpad (for the nonpreferred hand) and a mouse (for the preferred hand). To support the latter technique, we introduce a new input device, the TouchMouse, which is a standard mouse augmented with a pair of one-bit touch sensors, one for the palm and one for the index finger. Finally, we propose several enhancements to Buxton's three-state model of graphical input and extend this model to encompass two-handed input transactions as well. Keywords Two-handed input, three-state model, input devices, tablets, touchpads, TouchMouse, map navigation INTRODUCTION Two-handed input is a promising technique to improve the directness and degree of manipulation afforded by desktop computers. A strong foundation of re...

TiltType is a novel text entry technique for mobile devices. To enter a character, the user tilts the device and presses one or more buttons. The character chosen depends on the button pressed, the direction of tilt, and the angle of tilt. TiltType consumes minimal power and requires little board space, making it appropriate for wristwatch-sized devices. But because controlled tilting of one’s forearm is fatiguing, a wristwatch using this technique must be easily removable from its wriststrap. Applications include two-way paging, text entry for watch computers, web browsing, numeric entry for calculator watches, and existing applications for PDAs. KEYWORDS: Input/output devices, interaction techniques, wearable computing, mobile devices, text entry, accelerometer applications, wristwatch computers.

this paper, we develop and articulate a set of design principles for constructing - in a systematic and extensible manner - multi-hand gestures on touch surfaces that can sense multiple points and shapes, and can also accommodate conventional point-based input

In this paper, we explore how to add pointing input capabilities to very small screen devices. On first sight, touchscreens seem to allow for particular compactness, because they integrate input and screen into the same physical space. The opposite is true, however, because the user’s fingers occlude contents and prevent precision. We argue that the key to touch-enabling very small devices is to use touch on the device backside. In order to study this, we have created a 2.4 ” prototype device; we simulate screens smaller than that by masking the screen. We present a user study in which participants completed a pointing task successfully across display sizes when using a back-of device interface. The touchscreen-based control condition (enhanced with the shift technique), in contrast, failed for screen diagonals below 1 inch. We present four form factor concepts based on back-of-device interaction and provide design guidelines for extracted from a second user study. ACM Classification: H5.2 [Information interfaces and presentation]: User Interfaces. Input devices and strategies;

The mouse cursor acts as a digital proxy for a finger on graphical displays. Our hands, however, have ten fingers and many degrees of freedom that we use to interact with the world. We posit that by creating graphical cursors that reflect more of the hand’s physical properties, we can allow for richer and more fluid interaction. We demonstrate this idea with three new cursors that are controlled by the user’s fingers using a multi-point touchpad. The first two techniques allow for simultaneous control of several properties of graphical objects, while the third technique makes several enhancements to object selection. RÉSUMÉ Le curseur de la souris est un avatar digital pour notre doigt. Cependant, nos mains ont beaucoup plus qu’un seul doigt, ainsi que de nombreux axes de mouvement que l’on utilise pour manipuler notre environment. Nous postulons que la création d’un curseur graphique qui réflèterait encore plus d’aspects de la main permetterait des interactions plus riches et plus fluides. Nous démontrons cette idée avec trois nouveaux curseurs qui sont contrôlés en glissant plusieurs doigts à la fois sur une palette de digitalisation. Les deux premier curseurs manipulent les objects graphiques directement, alors que le troisième manipule la sélection des objects.

Recent advances in touch screen technology have increased the prevalence of touch screens and have prompted a wave of new touch screen-based devices. However, touch screens are still largely inaccessible to blind users, who must adopt error-prone compensatory strategies to use them or find accessible alternatives. This inaccessibility is due to interaction techniques that require the user to visually locate objects on the screen. To address this problem, we introduce Slide Rule, a set of audiobased multi-touch interaction techniques that enable blind users to access touch screen applications. We describe the design of Slide Rule, our interaction techniques, and a user study in which 10 blind people used Slide Rule and a button-based Pocket PC screen reader. Results show that Slide Rule was significantly faster than the button-based system, and was preferred by 7 of 10 users. However, users made more errors when using Slide Rule than when using the more familiar button-based system. Categories and Subject Descriptors:

Power wheelchair joysticks have been used to control a mouse cursor on desktop computers, but they offer no integrated text entry solution, confining users to point-and-click or point-anddwell with on-screen keyboards. But on-screen keyboards reduce useful screen real-estate, exacerbate the need for frequent window management, and impose a second focus of attention. By contrast, we present two integrated gestural text entry methods designed for use from power wheelchairs: one for joysticks and the other for touchpads. Both techniques are adaptations of EdgeWrite, originally a stylus-based unistroke method designed for people with tremor. In a preliminary study of 7 power wheelchair users, we found that touchpad EdgeWrite was faster than joystick WiVik, and joystick EdgeWrite was only slightly slower after minimal practice. These findings reflect “walk up and use”-ability and warrant further investigation into extended use.

We present Scratch Input, an acoustic-based input technique that relies on the unique sound produced when a fingernail is dragged over the surface of a textured material, such as wood, fabric, or wall paint. We employ a simple sensor that can be easily coupled with existing surfaces, such as walls and tables, turning them into large, unpowered and ad hoc finger input surfaces. Our sensor is sufficiently small that it could be incorporated into a mobile device, allowing any suitable surface on which it rests to be appropriated as a gestural input surface. Several example applications were developed to demonstrate possible interactions. We conclude with a study that shows users can perform six Scratch Input gestures at about 90 % accuracy with less than five minutes of training and on wide variety of surfaces. ACM Classification: H5.2 [Information interfaces and