The Question

Imagine that you are tasked with conveying data about industrial production rates over time to a lay audience. It needs to be quickly understood and easily remembered. You could use a simple standard bar chart. But another option is to transform the abstract numbers into concrete objects, depicting increasing car production as an increasingly taller stack of car icons.

This technique of stacking icons to represent data is called ISOTYPE visualization, and it has been around for a over 100 years.

Some visualization purists might bristle at such ‘chart junk’, seeking the minimalism of unadorned data. We studied whether the richer depictions of ISOTYPE visualizations actually carry benefits to a viewer.

We conducted five experiments on over 132 participants pitting ISOTYPE visualizations against more standard unembellished bar graphs. Here is a summary of our recommendations and the rationale behind them.