Avoid 3-D Charts for Excel Data Analysis
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.
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.
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.