Beyond the obvious
The importance of a proper scale

The graphical version of "to be seen"

In New York, there are many restaurants that serve mediocre food but which people go in to order to be seen. Here is the graphical equivalent, courtesy of Scientific American (link):



This is an attractive chart, but from which one should not expect to learn much.

The labels are well placed and unintrusive. The colors are not too sharp.

The size of the font draws our attention to the percentages -- the proportion of patents granted to China that falls into the specified categories. These percentages pertain to the single stacked column chart.

Looking right to left, the reader notices that the stacked column chart is an extension of the rightmost edge of the "ink blot". The ink blot is a variant of the stacked area chart. The massive growth between 1985 and 2010 looks mighty impressive. But the reader must navigate the transition from relative numbers to absolute numbers because the ink blot chart uses the number of patents, not the relative proportion.

In fact, the switch to absolute numbers leaves a void. The reader needs to know the relative proportion from decades past in order to interpret that single column representing just the year 2010. As the chart stands, has there been a change in distribution over time? Your bet is as good as mine.

I have previously explained why the ink blot chart is a silly invention. The central axis is arbitrary and meaningless. It's challenging to judge the growth from one year to another year because the growth is split in half and moving in different directions. The reader is asked to measure the vertical height at two points in time, and mentally shift the two line segments onto an even plane.

The other obstacle to understanding the rate of growth is the choice of scale. The exponential growth in recent years causes the earlier years to look completely flat.


 Furthermore, the taxonomy of patents is hard to grasp. There are two dimensions: purely Chinese invention versus co-invention; and assignment to {chinese indigenous firms only, or multinational firms only, or either, or other types of organizations}.

Without reading the article itself, it's hard to understand what the point of this taxonomy is. It's hard to learn anything from looking at this chart.

But it's nice to look at. That's for sure.


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