Speed-accuracy trade-off in dwell-based eye pointing tasks at different cognitive levels

Abstract

In this paper, we present a target searching experiment to investigate how long is long enough to maintain the speedaccuracy trade-off in eye pointing tasks that use dwell time as the activation mechanism. The experimental task, which took account of three factors including cognitive complexity, dwell time and visual feedback mode, mixes visual search and target acquisition together. In other words, the subjects need to search for and recognize the target before the final selection in each trial. The results clarify the suitable ranges of dwell time for users to avoid wrong selections as possible as they can under different cognitive load conditions. We also discussed the implications for user interface designs.

A Functional Usability Analysis of Appearance-Based Gaze Tracking for Accessibility

“…We are interested in evaluating how errors in gaze measurements affect selection by dwelling, and how to properly design a system that accounts for these errors. We are not considering here the dynamic aspects of this task, which can be described using variants of Fitt's law [Zhang et al 2010[Zhang et al , 2011. Rather, we look for the minimum diameter 𝐷 min of a circle around the target that ensures, with a certain probability 𝑃, that selection is triggered when the user is fixating the target for a period of time 𝑇 .…”

“…Intuitively, 𝐷 will need to be larger for noisy measurements, as noise may push measurements away from the point of fixation. In our experiments, we set 𝑇 , the dwelling time, to 700 ms, as this was found to be appropriate for simple tasks in prior research [Stampe and Reingold 1995;Zhang et al 2011]. We set 𝑃 to 0.9.…”