Evaluating the Speed and Accuracy of Touch Input at the Edge of a Table

Abstract

Tables, desks, and counters are often nearby, motivating their use as interactive surfaces. However, they are typically cluttered with objects. As an alternative, we explore touch input along the 'edge' of table-like surfaces. The performance of tapping, crossing, and dragging is tested along the two ridges and front face of a table edge. Results show top ridge movement time is comparable to the top face when tapping or dragging with the index finger. When crossing, both ridges are at least 11% faster than the top face. Effective width analysis is used to model performance and provide recommended target sizes. Based on observed user behaviour, we explore top and bottom ridge crossing using a "braced" thumb and provide design recommendations with example applications.