The hate of pie charts harms good data visualization…

…and why you should change the way you look at them.

How many articles on “how bad pie charts are” or “why should not use them”? On this platform only, if you type “pie charts” most of the entries will be against the use of those charts.

As we should do for everything, let’s stop having preconceived ideas and hate before questioning ourself on the matter.

I am not here to say if it’s bad or not to use such a chart, you can read about it here. I would like to change perspective, to see if we can have a better understanding of why they are so ubiquitous (despite the hate), why they work, and if we can better know how to use them from this thinking process.

WTFviz — DO NOT DO THAT!

Why the hate?

The main reason why pie charts are the target of visualization critics is that they are everywhere! From TV news to web info-graphics and economic newspaper… It is the “by default” choice, or at least an easy-to-go solution, for visualizing multiple values. Therefore they are often misused.

Pizza topping — original post
Pie & bar chart comparison with close values

In defence of pie charts

Despite all the hate towards pie charts, you can also find articles that defend the lovely shaped charts. Here are some examples of what you can find:

Why do they work? The doughnut, the watch and the pie.

If some smart people take the time to defend pie charts, it’s because they work in some instances and are the best solution for visualizing proportions, quickly and potentially several at the same time. We know that, but the reasons why they work and are (over) used, are not always examined. I think understanding that could help us to better use them.

Arthur Buxton — Gauguin’s paintings colours pie chart. Self-explainable, most of pie chats need minimal labelling.

The doughnut: the appeal

Doughnuts by Jack Lyons
Self-description by xkcd

The watch: the habit

Watch by DesignMilk
Pie

The pie: the multi-dimensions

Pies are good because easy to make, look good, easy to share and both the pastry and the mixture are tasteful. Pie charts also work because multiple aspects match well together: they are consistent.

The multi-dimensionality of pie charts

Take home message

Pie charts are everywhere because they work, and they work because we know how to read them, they are appealing, and they are quick to process. The consistency of their multiple dimension makes pie charts unique in the world of chart types.

Modeller by training, data visualization and statistics aficionado by the love of seeing hidden things.