Useful junk?

TLDR

Guidelines for designing information charts often recommend removing “chart junk”—visual embellishments that are not essential to understanding the data. The study investigates whether elaborate chart imagery harms or benefits comprehension and recall by comparing embellished charts to plain ones and measuring interpretation accuracy and long‑term recall. The experiment compared embellished charts with plain ones, measuring interpretation accuracy and long‑term recall over a two‑to‑three‑week interval. Accuracy was unchanged, but recall after two‑to‑three weeks was significantly better for embellished charts, suggesting that visual embellishment may not be detrimental and may even aid memory.

Abstract

Guidelines for designing information charts (such as bar charts) often state that the presentation should reduce or remove 'chart junk' - visual embellishments that are not essential to understanding the data. In contrast, some popular chart designers wrap the presented data in detailed and elaborate imagery, raising the questions of whether this imagery is really as detrimental to understanding as has been proposed, and whether the visual embellishment may have other benefits. To investigate these issues, we conducted an experiment that compared embellished charts with plain ones, and measured both interpretation accuracy and long-term recall. We found that people's accuracy in describing the embellished charts was no worse than for plain charts, and that their recall after a two-to-three-week gap was significantly better. Although we are cautious about recommending that all charts be produced in this style, our results question some of the premises of the minimalist approach to chart design.