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Examples of bad data visualizations

What would you consider a bad chart? In this article, Paula gives examples of some bad charts.
Examples Of Bad Data Visualizations
© paula guilfoyle

This pie chart was used in a presentation to show the US smartphone market share. Apple and the iPhone at the time having 19.5% of the market share. However, when you look at this pie chart, it looks like the 19.5% slice is bigger than the 21.2% slice. Apple has been blasted across different media outlets for use of the graph as it is very misleading. 3d pie chart source

This next chart was shown to you at the beginning of this week 3d column chart source

This is another bad example of a chart. 3D charts are notorious for being difficult to read and the creator is more focused on design than readability. It is impossible to see the sales of Lemons for all the months. Except for apples, it is hard to see the sales for all the products. takes a little work to read this chart. A user should not have to spend ages trying to work out the values, and in this case, the values are not obvious.

Now, look at this chart. It shows both relationships and composition. Look at the chart for 10 seconds and then try and explain what information is communicated to you. Do you think this is a good or bad chart?

hard chart to read


10 seconds is not long enough to get any meaning from this chart. There is just way too much going on. There are two stories being told. One of the relationships and one of composition. Eyes are drawn to the cluster, but this is too busy to make any sense out of in 10 seconds, leaving no time to review the composition. And even if there was time, the composition seems to be divided into categories and subcategories and there are way too many labels.

© paula guilfoyle
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Introduction to Excel Charts for Data Visualisation

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