Assessing 2D and 3D Heatmaps for Comparative Analysis

Abstract

Heatmaps are a popular visualization technique that encode 2D density distributions using color or brightness. Experimental studies have shown though that both of these visual variables are inaccurate when reading and comparing numeric data values. A potential remedy might be to use 3D heatmaps by introducing height as a third dimension to encode the data. Encoding abstract data in 3D, however, poses many problems, too. To better understand this tradeoff, we conducted an empirical study (N = 48) to evaluate the user performance of 2D and 3D heatmaps for comparative analysis tasks. We test our conditions on a conventional 2D screen, but also in a virtual reality environment to allow for real stereoscopic vision. Our main results show that 3D heatmaps are superior in terms of error rate when reading and comparing single data items. However, for overview tasks, the well-established 2D heatmap performs better.

Immersive Analytics with Abstract 3D Visualizations: A Survey

“…Kraus et al . [KAB*20] conducted a study on 3D heightmap visualizations for comparative analysis tasks and compared them with juxtapositioned 2D heatmaps. Their results indicate a potential benefit of immersive environments for certain comparative tasks, such as estimating the relative offset of given locations in heatmaps.…”

The Value of Immersive Visualization

“…For example, in the comparative analysis of 3-D distri butions of abstract dat a, t he immersive, spatialized 3-D variant with superpositioned 3-D heatmaps was superior to t he juxtapositioned 2-D variant in certain tasks. 8 As shown in Figure 5, the vertical layout combined with the encoding of values on heightmaps facilitates the comparison of the two distributions. The user can slide one dist ribution through the other to identify correlations, offset s, and general trends.…”

“…FIGURE5. Abstract data are spatialized, displayed as stacked 3-D heightmaps, and observed in VR for comparative analysis 8. …”

Toward Mass Video Data Analysis: Interactive and Immersive 4D Scene Reconstruction

“…For instance, Donalek et al reported a better perception of the datascape geometry in graph visualizations when participants were immersed in VR [ 45 ]. Further benefits have been identified in terms of data validation [ 46 ], collaboration [ 45 ], increased task performance on specific data exploration tasks [ 47 , 48 ], and memorability [ 49 ]. Etemadpour et al found that especially surface-based visual encodings profited from a stereoscopic perception in VR [ 50 ].…”