March 16, 2012

Fixing Nielsen’s bubbles (and tips for effectively organizing and displaying data)

The chart below comes from a recently released study by Nielsen.  With some simple fixes, this data can communicate much more effectively.

I find this chart hard to read and interpret because:

  1. The data is not aligned vertically, making comparisons across categories for the same country difficult.  For example, your eyes are constantly pinging left to right to left trying to compare the UK values.  It kind of makes me feel like I’m in a tennis match.
  2. The bubbles are not sized according to their percentage, making comparing bubble sizes meaningless and inaccurate.  You can’t tell me that the orange Italy bubble for Downloaded Music is 1/3 the size of the US bubble.
  3. There doesn’t seem to be any logic to the order of the categories.  At first I thought they were sized by the US percentages, but that’s not it.  Maybe they’re ordered by the total?  Nope.  I have no idea!

There are two better alternatives for presenting this data.  First, if you like the bubbles, then a viz like this works. 


With this viz, it’s so much easier to compare values both across and down.  It’s easier to compare bubble sizes, you don’t have to lookup the colors since they’re organized in columns, and the bubble sizes are relative to each other.  Look at Downloaded Music in Italy now: 20% now looks like it’s a bit less than 1/3 the size of the US bubble (62%).

Note that I would normally have ordered the categories alphabetically, but I sorted them in the same order as the Nielsen viz so that you could compare the mine and their’s more easily.

A second alternative would be a simple bar chart like this.


This chart also addresses the comparison problems.  The gridlines make it especially easy to compare categories within the same country, though your eyes do have to skip over three other bars before getting to the next one.

Bar lengths are much, much easier to compare than bubble sizes, but the bar chart feels a bit more cluttered to me than the bubble chart.  In this situation, I would use the bubble chart I created. 

This goes to show that there’s more than one way to skin a cat.