Using dynamic circles and squares to visualize spatio-temporal variation

TL;DR

This paper investigates how dynamic circles and squares in visualizations affect human perception of data on spatio-temporal maps, providing guidelines for more accurate visual encoding.

Contribution

It evaluates the impact of shape and metric choices on perception accuracy, offering new insights for designing effective visualizations.

Findings

Certain shape-metric combinations improve judgment accuracy

Shape choice influences perception due to visual illusions

Recommendations for visualization design are provided

Abstract

Visualizations such as bar charts, scatter plots, and objects on geographical maps often convey critical information, including exact and relative numeric values, using shapes. The choice of shape and method of encoding information is often arbitrarily, or based on convention. However, past studies have shown that the human eye can be fooled by visual representations. The Ebbinghaus illusion demonstrates that the perceived relative sizes of shapes depends on their configuration, which in turn can affect judgements, especially in visualizations like proportional symbol maps. In this study we evaluate the effects of varying the type of shapes and metrics for encoding data in visual representations on a spatio-temporal map interface. We find that some combinations of shape and metric are more conducive to accurate human judgements than others, and provide recommendations for applying these findings in future visualization designs.