1. Done
2. EFT or Paypal? (Oh, you said pay *attention*) Whups.
3. Pimping is an ongoing process.

I also was surprised to find that it was the simple pie chart that resulted in the most interesting discussion.

My thoughts:

Like any chart/graph, it comes down to what you’re using it for. If I had, say, 20 values, then no, I wouldn’t use a pie chart, but that’s a given.

If I want people to read _exact_ values, then I use a bar chart or something else that’s linear. However, it’s usually the case that we’re after a general idea – a big picture – which pie charts do just fine with, and not nearly as poor as some would make it out to be.

What if I removed the numbers from the above graphic? We’d still know that Excel and R dominate, the rest make up near half, and that Actionscript, Processing, and SAS had good showings. After all, when I cut a slice of literal cherry pie for myself and one that’s twice as big for my friend billy bob over there, I can tell the bigger slice is… bigger. The difference between 6% and 7% doesn’t matter so much.

So what was the purpose of the above graphic? Fun of course :)

Re 80 years of “no definitive findings”: I would think that if pie charts were effective, there would have been a definitive judgment or even consensus in their favor, and we would not be having this debate.

Angles, areas, and arc length are less effective at showing values than linear dimensions and positions (see Cleveland and more). The fact that pie charts use all of these does not seem to help the argument.

“As for the argument, “people underestimate their effectiveness” I would agree :-)”

Unfortunately, I meant to say ‘OVERestimate”. This is a consequence of their omnipresence and overuse.

Re data density, the bar chart I offered is 40% the size of Nathan’s pie, and offers twice the raw data values. In this case it is not an important point: Nathan used a large chart for emphasis. However, in addition to their low data density, pie charts can only handle a low data complexity: one series, effective maximum of around a half dozen points. A line/column chart can convey multiple series and even multiple dimensions, not through 3D effects but through multiple series and compound category axis layout.

P.S. Props to your comments being in the bright pink box. Weren’t people taking notice of you…?

An argument like “it’s harder to estimate areas than lengths” oversimplifies matters. A good pie chart simultaneously encodes data with angles, areas, and arc length. Unless you can cite a study that specifically looks at this redundant encoding, you’re not advancing the debate. Furthermore, it’s not even clear that precise communication of data is the most important issue. (After all, a table is the most precise thing you can have, but everyone still likes bar charts).

Statements like “They have one purpose: to show parts of a whole, and aren’t very good at that” are easy to make but hard to back up. Show me the study that supports this statement: if you read the Few and Spence articles, you’ll see that in fact the literature is thoroughly mixed.

As for the argument, “people underestimate their effectiveness” I would agree :-)

The point about information density is bizarre. There’s only a certain amount of information to be had here: do you want Nathan to make up more numbers or something? Or do you want him to shrink the chart? The concept of information density is not meant to be taken literally–otherwise we’d have the absurd idea that this chart would be better as a 30×30 icon. Nathan’s chart is fine as is: big, clear, eye-catching, easy to read.