Avoid 3-D Charts for Excel Data Analysis

By Stephen L. Nelson, E. C. Nelson

In general, and perhaps contrary to the wishes of the Microsoft marketing people, you really want to avoid three-dimensional charts for Excel data analysis. The problem with 3-D charts isn’t that they don’t look pretty: They do. The problem is that the extra dimension, or illusion, of depth reduces the visual precision of the chart. With a 3-D chart, you can’t as easily or precisely measure or assess the plotted data.

This figure shows a simple column chart.

A 2-D column chart.

A 2-D column chart.

The following figure shows the same information in a 3-D column chart. If you look closely at these two charts, you can see that it’s much more difficult to precisely compare the two data series in the 3-D chart and to really see what underlying data values are being plotted.

A 3-D column chart.

A 3-D column chart.

Those people who really like 3-D charts say that you can deal with the imprecision of a 3-D chart by annotating the chart with data values and data labels. The following figure shows the way a 3-D column chart would look with this added information. That’s not a good solution because charts often too easily become cluttered with extraneous and confusing information. Adding all sorts of annotation to a chart to compensate for the fundamental weakness in the chart type doesn’t make a lot of sense to me.

Adding too much detail to 3-D charts can make them hard to read.

Adding too much detail to 3-D charts can make them hard to read.