I’d like to ban pie charts. I know it’s a bit over the top, but I honestly can’t see a single thing they do better than other graph type (like a 100% stacked bar). They are also hopeless at lots of other things, namely:
- You can’t trend with them. Yes, you can put a few sad pies in a line, but you just don’t get the same instant understanding as a line chart or a bar chart. It’s very rare that we just look at one set of data, normally we are looking to see changes (or to inspire change).
- They are really hard to read when some segments are much bigger than others, the smaller values get rapidly drowned by the line thickness.
- You can’t put target points on them
I’ve noticed the software vendors seem to love them. I’m guessing that’s because you can make 3 random pieces of data occupy lots of screen space in a very colourful way.
Here’s the same data set as used in the pie chart above, but with the other 11 months of data added. It takes up little more space, is at least as easy to understand but has 12 times more data points to give trend insight:
Just don’t get me started on 3d pie charts…..