Judgments of Size Change Trends in Static and Animated Graduated Circle Displays

Abstract

Despite the abundance of research on the perception of information presented as graduated or proportional circles on static maps, such experiments have been rare for animated map displays. However, such experimental results might be beneficial for selecting optimal methods for depicting temporal change on graduated circle maps. In the present experiment, participants judged whether a greater number of circles in an n x n array increased or decreased during a 1500-millisecond (ms) observation interval. The variable n represented values of 6, 8, and 10,and all circles changed size (some larger, some smaller) from a common starting size either in a discrete shift (static condition) in the middle of the observation interval, or in a smooth, apparently continuous shift (animated condition) over the same interval. In addition, the size changes were relatively small, moderate, or large. The proportion of “more bigger” judgments, plotted against the actual proportions of enlarged circles, produced an ogive function (a cumulative normal) with similar slopes in all conditions. However, the bias towards “bigger” judgments increased with the size discrepancies between the initial and final circle diameters, and the bias towards “bigger” judgments was greater for animated than for static circle diameter changes. The results are interpreted in terms of attentional precedence for larger items and also for those that appear to be continuously increasing in size (looming). These results have implications for the presentation of information on static and animated graduated circle maps.