Using Variable Dwell Time to Accelerate Gaze-Based Web Browsing with Two-Step Selection

Abstract

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.

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“…Probably the most common example is eye-typing [15,16,18,19,25,28]. Other applications include object selection on interfaces [12] and in real world [26], target search and selection [28], computer game control (ranging from simple puzzles [1] and classical games [6] to role-playing and first-person shooter video games [11,27]), facilitating attention switching between multiple visual displays [13], robotic device control [7], web-browsing [5,14], interacting with geographic information systems [3], developing interactive graphical user interface elements [20], projected display control in automotive and military aviation environments [23].…”

“…Using gaze as an input method may not be comparable to the universal mouse and keyboard [14] because of the nature of the human eye movements and the physiology of the eye [17], yet it can still have several advantages. For people with physical disabilities gaze-based interaction provides a means to communicate and interact with technology and other people [5,6,17,18,20]. The performance of children with disabilities can be enhanced considerably through gaze controlled computers [10].…”

“…In contrast, controlling by gaze also faces considerable challenges [17]. Probably the most common issue is the Midas Touch problem [1,3,4,5,7,12,14,17,18,20,23,26,27], i.e. activating a command involuntarily only by looking at a specific target.…”

“…When using gaze as input, there is no natural counterpart of a mouse click [6,12,20]. For systems using solely gaze-based control for selection the most obvious and common alternative is dwell time [1,4,5,11,12,14,15,16,17,18,19,28], i.e. gazing at a specific object for a sufficiently long time to trigger an activation command.…”

“…Eye movements can be divided into several different categories [5,12,16,17]. Saccades are the most common way of moving the eyes in a sudden, ballistic way of 2 degrees or larger taking about 30-120 ms each.…”