I sat through a really interesting and engaging presentation earlier this week but for some reason the overriding memory I have is that it had a lot of pie charts and they weren’t very easy to read. To his credit, the presenter acknowledged this but I was left wondering if he was aware of an alternative.
I’m not about to lambast pie charts or people who use them but I am going to say that since I started taking more of an interest in the topic of information presentation I no longer use them.
It is easy to forget that working with Business Intelligence tools all day long provides us with exposure to what is considered best practice for conveying information visually through charts. So this post is for anyone who might be unsure how to display information currently shown in a pie chart in some other manner.
So what is wrong with this pie chart?
I picked this one because of all the examples I found, it was the closest to the type I saw earlier this week. In his excellent article Save the Pies for Dessert, Stephen Few asserts that in the above pie chart example, we can only judge the 25% green slice easily, the magnitude of the remaining ones are difficult to discern and of course the very small slivers are even more difficult to identify and estimate. There is also the issue of associating the slices of colour with the legend on the right and having to hop back and forth between the two in order to interpret the information.
How else could I display this information?
If the same data is presented in a bar chart as Few points out, ‘the values can now be compared with relative ease and precision, relying solely on the graph’ . To me the result is cleaner, more visually pleasing and much easier to interpret.
I couldn’t finish without a word from the master himself…
‘A table is nearly always better than a dumb pie chart; the only worse design than a pie chart is several of them’ - Edward Tufte - The Visual Display of Quantitative Information, 2001
and if you’re still reading, there are some great quotes in this blog entry by Coda Hale - what an awesome name that guy has 
Best heading for attention grabbing that I have seen in a long time …I was about to go on with a rant that Pies cannot be more Australian … warm beer and cold pie at the footy etc, but you had me fooled. I had to read your article as well .. Pie “charts” do also have their place. I suggest with less than three variables.