Abstract: Effective mode-switching techniques provide users of tablet interfaces with access to a rich set of behaviors. While many researchers have studied the relative performance of mode-switching techniques in these interfaces, these metrics tell us little about the behavior of one technique in the absence of a competitor. Differing from past comparison-based research, this paper describes a temporal model of the behavior of a common mode switching technique, non-preferred hand mode switching. Using the Hick-Hyman Law, we claim that the asymptotic cost of adding additional non-preferred hand modes to an interface is a logarithmic function of the number of modes. We validate the model experimentally, and show a strong correlation between experimental data and values predicted by the model. Implications of this research for the design of mode-based interfaces are highlighted.