Smart Touch: Improving Touch Accuracy for People with Motor Impairments with Template Matching

We present two contributions toward improving the accessibility of touch screens for people with motor impairments. First, we provide an exploration of the touch behaviors of 10 people with motor impairments, e.g., we describe how touching with the back or sides of the hand, with multiple fingers, or with knuckles creates varied multi-point touches. Second, we introduce Smart Touch, a novel template-matching technique for touch input that maps any number of arbitrary contact-areas to a user's intended (x,y) target location. The result is that users with motor impairments can touch however their abilities allow, and Smart Touch will resolve their intended touch point. Smart Touch therefore allows users to touch targets in whichever ways are most comfortable and natural for them. In an experimental evaluation, we found that Smart Touch predicted (x,y) coordinates of the users' intended target locations over three times closer to the intended target than the native Land-on and Lift-off techniques reported by the built-in touch sensors found in the Microsoft PixelSense interactive tabletop. This result is an important step toward improving touch accuracy for people with motor impairments and others for whom touch screen operation was previously impossible.