1 A-Coord Input: Coordinating Auxiliary Input Streams for Augmenting Contextual Pen-Based Interactions

The human hand can naturally coordinate multiple finger joints, and simultaneously tilt, press and roll a pen to write or draw. For this reason, digital pens are now embedded with auxiliary input sensors to capture these actions. Prior research on auxiliary input channels has mainly investi-gated them in isolation of one another. In this work, we explore the coordinated use of two auxiliary channels, a class of interaction techniques we refer to as a-coord input. Through two separate experiments, we explore the design space of a-coord input. In the first study we identify if us-ers can successfully coordinate two auxiliary channels. We found a strong degree of coordination between channels. In a second experiment, we evaluate the effectiveness of a-coord input in a task with multiple steps, such as multi-parameter selection and manipulation. We find that a-coord input facilitates coordination even with a complex, afore-thought sequential task. Overall our results indicate that users can control at least two auxiliary input channels in conjunction which can facilitate a number of common tasks can on the pen. Author Keywords Pen-based interaction, pen roll, pen pressure, pen tilt, dual