Visual Arrangements of Bar Charts Influence Comparisons in Viewer Takeaways

Abstract

Well-designed data visualizations can lead to more powerful and intuitive processing by a viewer. To help a viewer intuitively compare values to quickly generate key takeaways, visualization designers can manipulate how data values are arranged in a chart to afford particular comparisons. Using simple bar charts as a case study, we empirically tested the comparison affordances of four common arrangements: vertically juxtaposed, horizontally juxtaposed, overlaid, and stacked. We asked participants to type out what patterns they perceived in a chart and we coded their takeaways into types of comparisons. In a second study, we asked data visualization design experts to predict which arrangement they would use to afford each type of comparison and found both alignments and mismatches with our findings. These results provide concrete guidelines for how both human designers and automatic chart recommendation systems can make visualizations that help viewers extract the "right" takeaway.

How Do Viewers Synthesize Conflicting Information from Data Visualizations?

“…Additionally, we controlled for the type of visualization used by asking participants to read similar line charts with overlaid scattered dots. These design choices limit our ability to generalize our findings to other visualization types, as visualization techniques can profoundly impact human perception and decision-making [93,94,96]. Furthermore, we did not vary the number of data points in the current experiments and only asked participants to synthesize two pieces of information.…”

Comparison Conundrum and the Chamber of Visualizations: An Exploration of How Language Influences Visual Design

“…Cardinality: Comparison utterances can express relationships between individual entities, e.g., "compare the effectiveness of treatment A to treatment B", as well as relationships between individuals and larger sets containing multiple entities, e.g., "compare the effectiveness across all treatments". Similar to the process described by Xiong et al [69], we list four cardinalities for the entities in comparison utterances in the context of visual analysis:…”

“…2. Examples of two sets of spatial arrangements for visual comparisons based on findings from Xiong et al [69]. Results found that stacking small multiples vertically tends to elicit 1-to-1 comparisons of individual values in a set, whereas aligning them horizontally tends to elicit a comparison of the two sets as two groups.…”

“…E-mail: jhoffs@adobe.com. design choices in a visualization can nudge viewers to see different patterns and produce different sentences [13,69], further highlighting the complexities and nuances of comparison tasks. For example, Figure 2 shows how the juxtaposition of small multiples, either vertically or horizontally, can elicit different comparisons across the two groups.…”

“…mendation system that can help users more easily make comparisons in visualized data. First, designing a visualization involves a series of decisions, each of which can afford different viewer takeaways [69,72].…”