The common explanation for how pie charts work is that we read them by angle. That of course would mean that donut charts would be bad, because you can’t see the angle when you take away the center of the pie. Changing the radius of a slice wouldn’t matter though, because that doesn’t change the angle. But there is no evidence that angle is how we read pie charts, quite the opposite actually. In this new video, I walk through five reasons why angle is not how we read pies, and what that means for other things we like to assume about them.

[Read more…] about New Video: The Science of Pie Charts# pie charts

## eagereyesTV Episode 3: 3D Pie Charts For Science!

How do we read pie charts? This seems like a straightforward question to answer, but it turns out that most of what you’ve probably heard is wrong. We don’t actually know whether we use angle, area, or arc length. In a short paper at the VIS conference this week I’m presenting a study I ran to answer this question – a study using 3D pie charts!

[Read more…] about eagereyesTV Episode 3: 3D Pie Charts For Science!## Paper: Evidence for Area as the Primary Visual Cue in Pie Charts

How we read pie charts is still an open question: is it angle? Is it area? Is it arc length? In a study I’m presenting as a short paper at the IEEE VIS conference in Vancouver next week, I tried to tease the visual cues apart – using modeling and 3D pie charts.

[Read more…] about Paper: Evidence for Area as the Primary Visual Cue in Pie Charts## Two Short Papers on Part-to-Whole Charts at EuroVis

Why do pie charts look the way they do? What makes this particular way of slicing up a circle the preferred way of showing part-to-whole relationships? In two short papers that I’m presenting this week at EuroVis, I looked at the design space of circular part-to-whole charts, including pie charts.

[Read more…] about Two Short Papers on Part-to-Whole Charts at EuroVis## Talk: Pie Charts – Unloved, Unstudied, and Misunderstood

I gave a talk at Information+ earlier this year that has now been posted. It’s about pie charts! And it was a fun talk, too. [Read more…] about Talk: Pie Charts – Unloved, Unstudied, and Misunderstood

## A Reanalysis of A Study About (Square) Pie Charts from 2009

After my recent posting on the results of our pie charts studies, Jorge Camoes teased me on Twitter about square pie charts. So I dug up the data from a study we ran many years ago to look at how well they compare to bars, pies, and squares. [Read more…] about A Reanalysis of A Study About (Square) Pie Charts from 2009

## An Illustrated Tour of the Pie Chart Study Results

In two papers, Drew Skau and I recently showed that our idea of how we read pie charts is wrong, that donut charts are no worse than pie charts, and a few more things. Here is a detailed walk-through of the results of the three studies we conducted for this purpose. Let’s go on a little journey through some real data and do a little science together! [Read more…] about An Illustrated Tour of the Pie Chart Study Results

## A Pair of Pie Chart Papers

How do we read pie charts? Do they differ from the even more reviled donut charts? What about common pie chart designs like exploded pies? In two papers to be presented at EuroVis next week, Drew Skau and I show that the common wisdom about how we read these charts (by angle) is almost certainly wrong, and that things are much more complicated than we thought. [Read more…] about A Pair of Pie Chart Papers

## Ye Olde Pie Chart Debate

You may think that the debate over pie charts was a new one, but it has raged on for at least 100 years. Brinton started it in 1914, and great drama unfolded in the pages of the *Journal of the American Statistical Association* in the 1920s. [Read more…] about Ye Olde Pie Chart Debate

## In Defense of Pie Charts

Pie charts don’t get much respect. They’re almost always considered the wrong choice by those supposedly in the know. But how do we know that this is true? What evidence do we have to support this? The truth is, not much. And when we start digging for proof, it turns out that pie charts are much better than we want to admit. [Read more…] about In Defense of Pie Charts