I’ve had enough pie [chart]!
In the May 21, 2007 issue of BusinessWeek, you can see an excellent example of how to improve presenting data. Below is a copy of the pie chart, which is titled, “The Other Banking System. A growing number of Americans seek financial services from alternative institutions”. Looking at this chart, it is difficult to quickly compare the seven different slices. Here are a few points why I think pie charts, in general, fall short:
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Shades of blue are hard to distinguish
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Handouts will be hard to read without a high-quality color printer
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Scale of slices are difficult to interpret and compare
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Takes much longer to create with all of the customization needed to make meaningful
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Can be too cluttered when you have many slices or use different colors for each slice
Check out the bar chart below that has the same data and only took me a few minutes to create using the Excel chart wizard. Formatting the pie chart takes a lot longer and is much more difficult. I find the bar chart is straightforward to read and is simple to create in MS Excel. For some reason people just gravitate to pie charts; probably because they are prettier. I would presume that the pie chart is just what everyone expects when trying to show data similar to the one above. By using the bar chart below, you can easily see the scale, highest and lowest percent, and labels.
Here is yet another option to use the in-cell graphics functionality that is very easy to create in MS Excel. This is my personal favorite and is simple to format to your liking. The charts in Figure 2 and 3 reduce “chartjunk”, a popular term coined by Edward Tufte that simply means “unnecessary or confusing visual elements in charts and graphs.” [Wikipedia]
After looking at these three options for presenting the same data, which one do you think is the most effective?
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June 6th, 2007 at 4:52 pm
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September 17th, 2008 at 1:22 am
though I agree with your oppion, that the figure 3 is best , but in some case, the figure 1 ,the pie chart is appropriate。Imagining that , in a biz magzine,there is no pie chart ,only the gray bar chart ,what a monotonous thing !
September 17th, 2008 at 10:06 am
You make a good point with the data given. The gray bar chart is not that exciting, but it is effective. The post is to reiterate that pie charts are not an effective means of displaying quantitative information. There are flaws that many experts like Stephen Few and Edward Tufte have noted with regards to pies.
I think there can be bar charts that add more flare without taking away from the effectiveness of the data visualization.
Thank you for the comment!
September 17th, 2008 at 2:32 pm
Tony – A little flair goes a long way. If you have to dress up the data, it’s probably not worth showing. If you don’t have to dress it up, it can stand on its own.
Excel Pro – I challenge you to show me a pie chart that is appropriate for its purpose. Other than a two wedge pie, to show relative proportions of two categories, you won’t find anything.
September 17th, 2008 at 2:38 pm
Jon, it’s nice to see your face (literally) on here.
I didn’t mean any chartjunk. However, the use of some color to illustrate the current period or current and prior period may help to make it less boring. Pick up any company annual report and you will find colors galore. I can relate to what ExcelPro is suggesting. You will actually find a lot of annual reports now going to black and white with all text and tables.
I wouldn’t go so far as to say that I would dress up the data by using a pie chart, but I may use some color in a bar or column chart.
Thanks for the comments!