Using Variable Dwell Time to Accelerate Gaze-based Web Browsing with Two-step Selection

In order to avoid the “Midas Touch” problem, gaze-based interfaces for selection often introduce a dwell time: a fixed amount of time the user must fixate upon an object before it is selected. Past interfaces have used a uniform dwell time across all objects. Here, we propose an algorithm for adjusting the dwell times of different objects based on the inferred probability that the user intends to select them. In particular, we introduce a probabilistic model of natural gaze behavior while surfing the web to infer the probability that each hyperlink is the intended hyperlink. We assign shorter dwell times to more likely hyperlinks and longer dwell times to less likely hyperlinks, resulting a variable dwell time gaze-based browser. We have evaluated this method objectively both in simulation and experimentally, and subjectively through questionnaires. Our results demonstrate that the proposed algorithm achieves a better tradeoff between accuracy and speed.