Motion is the visible change of a visual element over time. In data visualization, it is a preattentive attribute: viewers notice movement quickly, often before consciously inspecting the rest of the display. section 2.1.4 section 2.0
Use motion when change itself matters or when attention needs a gentle nudge. Treat it carefully, though: animation can grip an audience without necessarily supporting analysis, and excessive movement can distract or slow the page. section 2.1.4 section 2.3
Practical guidelines:
- Use motion sparingly so important changes stand out rather than competing with everything else. section 2.3
- Use animation as interaction feedback: grow or shrink bars, redraw lines, rearrange elements, or show a loading spinner. section 7.1.3
- Keep feedback visible at or near the interaction point, and prevent it from slowing the page or becoming distracting. section 7.1.3
Motion across time
Gapminder’s World Health Chart animates bubbles representing countries as income and life expectancy change across years. The motion makes historical shifts vivid, including sharp life-expectancy declines during the late 1910s and early 1940s. Racing bar charts offer a flashier alternative: they attract attention strongly, but are less useful for analysis. section 2.1.4
Figure 7.3 Some ways to show the user that their interaction has changed the data being displayed are to change labels such as titles, move a highlighter box, and/or change font styling.
See how interaction feedback can combine animation with changing labels, moving highlights, or altered font styling. section 7.1.3
