Lost in Magnitudes: Exploring Visualization Designs for Large Value Ranges
Katerina Batziakoudi, Florent Cabric, Stéphanie Rey, Jean-Daniel Fekete
TL;DR
The paper presents a design-space approach for visualizing order-of-magnitude values by separating mantissa and exponent, guided by perception research and GoG principles. It introduces the EplusM scale and the Facet encoding, and systematically generates and qualitatively evaluates a wide set of designs, deriving four core guidelines (AcM, DeM, CoM, PaC). Through a crowdsourced experiment comparing EplusM and Facet against linear, logarithmic, and the Scale-Stacked Bar Chart, the authors demonstrate that mantissa–exponent visualizations can achieve comparable or superior accuracy, speed, and confidence for quantitative OMV tasks, particularly when comparing values within similar magnitudes. The work advances OMV visualization practice, provides an open-source tool (OMVis) and data, and outlines future directions for expanding the design space, incorporating interactivity, and broadening audiences. Overall, the study argues that preserving the two-component structure of OMVs while employing collinear positional encodings can enhance precision and user understanding in large value-range visualizations.
Abstract
We explore the design of visualizations for values spanning multiple orders of magnitude; we call them Orders of Magnitude Values (OMVs). Visualization researchers have shown that separating OMVs into two components, the mantissa and the exponent, and encoding them separately overcomes limitations of linear and logarithmic scales. However, only a small number of such visualizations have been tested, and the design guidelines for visualizing the mantissa and exponent separately remain under-explored. To initiate this exploration, better understand the factors influencing the effectiveness of these visualizations, and create guidelines, we adopt a multi-stage workflow. We introduce a design space for visualizing mantissa and exponent, systematically generating and qualitatively evaluating all possible visualizations within it. From this evaluation, we derive guidelines. We select two visualizations that align with our guidelines and test them using a crowdsourcing experiment, showing they facilitate quantitative comparisons and increase confidence in interpretation compared to the state-of-the-art.
