There are some charts that look so stunning and yet confusing. You cant make up your mind whether it tells a compelling story or it is just plain wrong.
Today, let me present you one such chart. I call this Pie of a Pie of a Pie chart (source: thiswoo, thanks to Nassar, our forum member for mentioning this)
Pie of pie of pie – What is good about it?
The idea of this chart is quite noble. Show how the water in this world is distributed. Obviously, with such large numbers, making one chart would be difficult. So make 3. The initial pie of salt vs. fresh water, which explodes to show the distribution of fresh water which explodes to show the spread of other water sources.
The chart narrates the story of how little water is available for consumption and where it is one simple picture.
And the pie leaking in to another pie metaphor works really well in this case.
What is not good about it?
To begin with, the 3D pies are very deceptive. It is not clear how much % of water is fresh water (other than the fact that it is very little). Also, compared to a 2d pie, the fresh water slice in 3d pie looks bigger (due to its orientation and 3d effects).
Then, no matter how good the colors are, the 2nd and 3rd pies are confusing. The colors imply that the blue slice (fresh water) corresponds to just ice caps and glaciers.
Since all 3 pies are of similar sizes, we immediately think that we have enough water. Only on closer inspection it becomes obvious that the size of lower pies has no relation to actual water amount (only angles convey the information).
Finally, I think this chart is bad because it takes excessively large amount of time to make in almost any software. That said, it is a good exercise to come up with this tinkering with various drawing shapes etc.
Aren’t there any alternatives?
The easiest and clear (and obviously not so exciting as pie of pie of pie chart) alternative is to just show the numbers like this:
Note: This table too is misleading as row heights wrongly indicate that we have more fresh water than salt water etc.
The next option is to use a variation of bar of bars, some thing like this:
One more option I can think of is a tree map. For hierarchical data like this Treemaps are also a very good option. That said, since the largest value is 390,000 times the smallest value, any treemap will be very large to show the smallest value clearly.
Do you like Pie of Pie of Pie chart?
What do you think? Do you love this or would you prefer some other chart to visualize this data? Share your opinion using comments.
Previously on Pie Charts
Pie charts are one of the most (mis)used charts in business world these days. That is why we talk about them from time to time. See these articles to learn more:
- An example where pie charts work well
- Alternatives to Pie charts
- Group smaller slices in pie charts to improve readability
- Do not make pie charts like these
PS: If you want to know to create this pie of pie of pie chart in excel, see here.