Selecting Small Targets With Gaze Alone: Is Zooming the Answer?

Abstract

<p>Selecting the smallest targets in mainstream graphical user interfaces (GUls) with gaze alone is difficult due to the limited pointing accuracy of gaze input when compared to mouse input. Approaches to address the limited accuracy of gaze pointing include those aimed at reducing the noise of the pointer (e.g., smoothing) and those aimed at increasing target tolerance (e.g., interface design). We focused on a subset of the second type of approaches: the design of interface tools that effectively increase the size of selectable objects in mainstream GUls. We proposed a conceptual framework to organize existing interface tools and guide the development of new tools. Inspired by our previous attempts to use continuous zoom tools to increase the effective size of selectable objects in mainstream GUls, we also designed a discrete zoom tool. To test the potential of our framework and tool, we conducted a proof-ofconcept experiment in which participants performed a point-and-select task with small targets (i.e., 6-and 12-pixel wide). We compared the participants' performance when using no tool (i.e., dwell), a two-step magnification tool (often available in commercial gaze-tracking systems), or one of two versions of our discrete zoom tool. One of these discrete-zoom-tool versions had the same magnification level and dwell time as the two-step magnification tool, whereas the other was optimized. Our results showed that the optimized discrete zoom tool was as fast as and more accurate than the two-step magnification tool. We conclude that our zoom framework shows potential to guide the design, development, and testing of tools to facilitate the accessibility of mainstream interfaces for gaze-input users. Furthermore, we argue that the use of discrete zoom tools that fall between the two ends of the spectrum (i.e., two-step magnification and continuous zoom) can potentially be helpful in certain gazeinteraction situations.</p><p>This presentation occurred at the Wright State University Campus-Wide Celebration of Research, Scholarship and Creative Activities on April 16, 2010</p>