Is It True That Humans Can’t Accurately Measure Areas?: Criticism and Misunderstandings About Bubble Charts (and Pie Charts)
Visualizations are often judged within the context of “good” vs. “bad”. There certainly are bad visualizations that fail to serve their purpose for specific objectives. However, the idea that there’s a single “good” visualization for any given purpose is simply not true.
Herein, I would like to talk about the criticisms and misunderstandings about bubble charts.
Bubble charts represent quantities with the size of circles.
Bubble charts are often presented as bad visualizations. A major reason is that ‘humans cannot accurately measure area.’ This issue is also cited as a reason why pie charts are considered poor visualizations.
I personally feel that it’s true, but why? What makes areas so special? What about volumes or logarithmic scales? Can you accept the explanation ‘This is the way humans are’ without any doubt?
Let’s speculate about it.
Example
The issue is discussed, for example, in “The Functional Art” (Chapter 2) by Alberto Cairo, published in 2012. Before I move on, I would like to note that this book is very well-written and I learned a lot from it.