Modeling the difficulty for centering rectangles in one and two dimensions

Abstract

Centering, positioning an object within specified bounds, is a common computer task, for example making selections using a standard mouse or on a touch screen using a finger. These experiments measured times for participants (n = 131) to position a rectangular cursor with various widths, p (10 px ≤ p ≤ 160 px), completely within rectangular targets with various widths, w, and tolerances, t = w-p (4 px ≤ t ≤ 160 px) in one and two dimensions. The analysis divides the movement time into two phases, the transport time and the centering time. Centering times are modeled well by 1/t. All models have high correlation, r 2 ≥ 0.95. © 2009 Springer Berlin Heidelberg.