stylus

This paper offers a solution to the mode problem in computer sketch/notetaking programs. Conventionally, the user must specify the intended "draw" or "command" mode prior to performing a stroke. This necessity has proven to be a barrier to the usability of pen/stylus systems. We offer a novel Inferred-Mode interaction protocol that avoids the mode hassles of conventional sketch systems. The system infers the user's intent, if possible, from the properties of the pen trajectory and the context of the trajectory. If the intent is ambiguous, the user is offered a choice mediator in the form of a pop-up button. To maximize the fluidity of drawing, the user is entitled to ignore the mediator and continue drawing. We present decision logic for the inferred mode protocol, and discuss subtleties learned in the course of its development. We also present results of initial user trials validating the usability of this interaction design.

In this paper we present a system for providing tactile feedback for stylus-based touch-screen displays. The Haptic Pen is a simple low-cost device that provides individualized tactile feedback for multiple simultaneous users and can operate on large touch screens as well as ordinary surfaces. A pressure-sensitive stylus is combined with a small solenoid to generate a wide range of tactile sensations. The physical sensations generated by the Haptic pen can be used to enhance our existing interaction with graphical user interfaces as well as to help make modern computing systems more accessible to those with visual or motor impairments.

We present the design and implementation of a word-level stroking system called Fisch, which is intended to improve the speed of character-level unistrokes. Importantly, Fisch does not alter the way in which character-level unistrokes are made, but allows users to gradually ramp up to word-level unistrokes by extending their letters in minimal ways. Fisch relies on in-stroke word completion, a flexible design for fluidly turning unistroke letters into whole words. Fisch can be memorized at the motor level since word completions always appear at the same positions relative to the strokes being made. Our design for Fisch is suitable for use with any unistroke alphabet. We have implemented Fisch for multiple versions of EdgeWrite, and results show that Fisch reduces the number of strokes during entry by 43.9% while increasing the rate of entry. An informal test of "record speed" with the stylus version resulted in 50-60 wpm with no uncorrected errors.

We present radial scroll, an interface widget to support scrolling particularly on either small or large scale touch displays. Instead of dragging a elevator in a scroll bar, or using repetitive key presses to page up or down, users gesture anywhere on the document surface such that clockwise gestures advance the document; counter clockwise gestures reverse the document. We describe our prototype implementation and discuss the results of an initial user study.