Abstract
Effective communication using visualization relies in part on the use of viable visual encoding strategies. For example, a viewer's ability to rapidly and accurately discern between two or more categorical variables in a chart or figure is contingent upon the distinctiveness of the encodings applied to each variable. Research in perception suggests that color is a more salient visual feature when compared to shape and, although that finding is confirmed by visualization studies, their data suggest characteristics of shape also yield meaningful differences in distinctiveness. We propose that open or closed shapes (that is, whether it is composed of line segments that are bounded across a region of space or not) represent a salient characteristic that influences perceptual awareness. Two experiments were designed to test the reliability of the open/closed dimension. In the first, a flanker paradigm was used to test whether perceptual load and open/closed feature dimension would modulate the effect of the flanker on target processing. Results showed an influence of both variables. The second experiment used a Same/Different RT task to replicate and extend those findings. Results from both show that responses are faster and more accurate when closed rather than open shapes are processed as targets; and there is more processing interference when two competing shapes come from the same rather than different open/closed feature dimensions. Our results bear implications for the visualization community and can inform recommendations in automated charting software.
Meeting abstract presented at VSS 2017