Comparing Pre-attentive Visual Variables in a Target Identification Task for Glanceable Visualizations

Keywords

pre-attentive visual variables, micro visualization, mobile visualizations, smartwatch.

Abstract

In this paper, we evaluated the use of three pre-attentive visual variables, namely, area, color hue, and flicker, to highlight elements on four charts: bar chart, line chart, linear progress chart, and radial progress chart. We exposed 48 participants---using short time lapses of 250 ms---to a set of stimuli showing one of the four charts with the three visual variables. Then we examined the accuracy of their answers in identifying the highlighted target element under sedentary and walking conditions. Our results show that all three visual variables can be perceived with a medium to high accuracy rate, though performance varies depending on the mobility condition, the visual variable, and even the chart type. Among the visual variables, color and flicker yield the best target identification accuracy rates, while the area proves to be the least effective. The findings from our first investigation contribute to the design of efficient smartwatch micro visualizations that support glanceable and in-motion data reading.