Material for the new edition - how to improve a graph

Here is something that I am intending to put in the new edition, showing how one can improve a graph to make it more readable and impart a message more clearly.  This will be in the form of a 'boxout', separated off from the main explanatory text.  When learning (about it any subject) it is useful to see examples of bad presentation as well as of good.  Do you think this is a useful example from which you learn something?  Add your comment below.

Improving the presentation of graphs - an example

Today we are assailed with information presented in the form of graphs, sometimes done well but often badly.  We give an example below of how presentation might be improved for one particular graph, showing employers’ perceptions of Economics graduates’ skills.  One can learn a lot from looking at examples of graphs in reports and academic papers and thinking how they might be improved. The original graph is not actually a bad one but it could be better.

Problems with this picture include:

1.     The category labels are difficult to read, being small and wrap-around text

2.     The vertical axis title is sideways, so difficult to read

3.     It is difficult to compare across categories.  For example, which skill has the most ‘very high’ or ‘fairly high’ responses?

4.     A subjective judgement, but the colours are not particularly harmonious.

The version below takes the same data but presents it slightly differently:

Turning the graph on its side means that the labels are much easier to read, as is the horizontal axis label.  Making it a stacked bar chart saves space and makes it look less cluttered.  It is fairly easy to see that ‘interpreting quantitative data’ scores the most ‘very high’ or ‘fairly high’ responses – hopefully this book makes some contribution towards that!  Using different shades of the same colour makes for a better appearance (and probably works better if printed in grayscale too).

You might have noticed that the categories are now in a different order.  This is a quirk of Excel, the same data table was used for both charts.  Fortunately the ordering does not matter.  We shall give similar examples at other places in this book.