Efficiency in space usage leads to efficiency in comprehension

Consider the following two charts that illustrate the same data. (I deliberately took out the header text to make a point. The original chart came from the Wall Street Journal.)

To me, the line chart gets to the point more quickly: that Burberry stores are more numerous in those places shown on the left and fewer in those places shown on the right, relative to comparable luxury brands (Prada and Louis Vuitton).

The reason why the tiled bar chart is tougher to decipher is its inefficient use of space. Within each country group,  the three places are plotted on two levels, one on the upper level, and two on the lower level. Then the two groups of countries are placed top and bottom. Readers have to first size up the individual group of three countries, then make a comparison between the two groups.

***

From a Trifecta checkup perspective, the bigger issue here is the data. The full story seems to be that those two country groups have different currency experiences... Japan and the continental European countries have weakening currencies, which tends to make their goods cheaper for Chinese consumers. This crucial part of the story is not anywhere on the chart.

In addition, the number of stores is not a telling statistic, because stores may have different areas, and certainly the revenues generated by these stores differ, potentially by country. A measure such as change in same-store sales in each country is more informative.

It is also not true that the distribution of stores is purely a matter of business strategy, as Burberry is a British brand, Prada is Italian and Louis Vuitton is French. They each have more stores in their home countries, which seems very logical.

Comments

[LemmusLemmus]

To me, line charts suggest changes over time.

[Shalin]

Cool charts, did you make them with Office software or creately diagram software ?

[jlbriggs]

After all these years...I still cannot get behind your use of line charts for categorical data in this manner.

A dot plot seems a much better idea.

At the same time, the problem with the original is the weird variation of a bar chart that they chose, and the fact that they removed on category from the base line.

A simple, well designed grouped bar or column chart would work just fine for this display, without confusing the user by adding a line between data points.

[jlbriggs]

Quick and dirty example as a normal column chart from Excel:

http://imgur.com/45ch35q

[Kaiser]

Shalin: that is made in Excel, with post-processing in Powerpoint. I like to tell people if you spend enough time in Excel/Powerpoint, you can make presentable graphics. It's not the most natural way of doing it but it is possible.

jlbriggs, lemmus^2, and others: let me explain my logic yet again, just for the sake of newer readers. When you read a grouped column chart like the one jlbriggs made (thank you!), your eyes are moving from the top of one column to the next, and the trajectory of your eyes is the line in the line chart. One side benefit of using the line chart is that it forces the designer to think carefully about ordering of the categories.

[Stef]

For me too, it's pretty strange to see categorical data displayed like the example above as a line chart. Really counterintuitive. However, I have as well to admit that it is indeed much easier to read (and looks more calm, smooth) when the line-chart is displayed directly vis-à-vis the above linked bar chart.