Toward Gaze-Based Map Interactions: Determining the Dwell Time and Buffer Size for the Gaze-Based Selection of Map Features

Abstract

The modes of interaction (e.g., mouse and touch) between maps and users affect the effectiveness and efficiency of transmitting cartographic information. Recent advances in eye tracking technology have made eye trackers lighter, cheaper and more accurate, broadening the potential to interact with maps via gaze. In this study, we focused exclusively on using gaze to choose map features (i.e., points, polylines and polygons) via the select operation, a fundamental action preceding other operations in map interactions. We adopted an approach based on the dwell time and buffer size to address the low spatial accuracy and Midas touch problem in gaze-based interactions and to determine the most suitable dwell time and buffer size for the gaze-based selection of map features. We conducted an experiment in which 38 participants completed a series of map feature selection tasks via gaze. We compared the participants’ performance (efficiency and accuracy) between different combinations of dwell times (200 ms, 600 ms and 1000 ms) and buffer sizes (point: 1°, 1.5°, and 2°; polyline: 0.5°, 0.7° and 1°). The results confirmed that a larger buffer size raised efficiency but reduced accuracy, whereas a longer dwell time lowered efficiency but enhanced accuracy. Specifically, we found that a 600 ms dwell time was more efficient in selecting map features than 200 ms and 1000 ms but was less accurate than 1000 ms. However, 600 ms was considered to be more appropriate than 1000 ms because a longer dwell time has a higher risk of causing visual fatigue. Therefore, 600 ms supports a better balance between accuracy and efficiency. Additionally, we found that buffer sizes of 1.5° and 0.7° were more efficient and more accurate than other sizes for selecting points and polylines, respectively. Our results provide important empirical evidence for choosing the most appropriate dwell times and buffer sizes for gaze-based map interactions.

Evaluating the Usability of a Gaze-Adaptive Approach for Identifying and Comparing Raster Values between Multilayers

“…More recently, Zhu et al [34] selected an area by determining the area that contains a user's current gaze. To select points, lines and areas for gaze interaction, Liao et al [35] examined various combinations of dwell time and buffer size. They discovered that buffer sizes of 1.5 • and 0.7 • are suitable for selecting points and lines, respectively, and that a dwell time of 600 ms provides a better balance between accuracy and efficiency than 200 ms and 1000 ms.…”

“…In this experiment, we devised tasks to simulate the demand of exploring the local features of the raster map. Based on the tracking accuracy of current devices and the recommended control size from prior research on gaze interaction [35,56], we established a size of 1 • for each block that participants were required to observe in this experiment. Meanwhile, we set the spatial resolution of the map to a lower level to ensure that the grid values were consistent within each block, thereby reducing potential ambiguity for participants during the task.…”