3 Cheating with charts
One of the reasons for using visualisation is that it allows us to ‘see’ what is going on in a data set, by providing a shorthand ‘at-a-glance’ way of exposing patterns or distributions, where the patterns or trends are graphically self-evident. However, depending on the visual context the data is provided in, the visualisation can sometimes be misleading. In this section, you’ll see a few ways in which graphical representations – specifically line charts, bar charts and pie charts – may be deliberately or carelessly misleading, and do more harm than good in the sense of miscommunicating information rather than failing to communicate it at all.
Before we get started, though, familiarise yourself with the range of ways in which people currently use bar charts, line charts and pie charts by trying the following activity.
Activity 4 (exploratory)
Try the following image searches on Google Images, or an image search engine of your choice:
and finally, “pie chart” on Google Images.
For each chart type, do the charts look broadly the same? What sort of variety is possible in the display of each chart type?
You may have been struck by how much variation there was in the use of colour and detail on the charts. You probably found that the quality and extent of labelling on the axes varied widely. You may also have found that some charts attempted to use 3D effects which looked pretty at first glance, but at a second look may have become quite distracting and even hard to read.