Think Before You Stack
I hate to beat this to death, but I continue to see charts like the one below featured in excellent periodicals like BusinessWeek. As I said in a previous post, I really dislike stacked bar charts, ESPECIALLY when time is on the x-axis. To help illustrate my point, here are a few questions:
1) How much did the Subprime (yellow) dollars change from month to month or between any points?
2) Is there even a value for Subprime after about March 2013?
3) How many times do you have to reference the legend to figure out which color is what label?
The only value that is easy to visualize and analyze is the Agency data that is in black and the first data series. Beyond Agency, this data visualization is useless. I tried to get the data to make a better chart, but couldn’t locate it. Instead I ask that you visualize 7 lines in a line chart, one for each value and the 7th one for the total. Using that chart, you could easily see the trend in each value and also the overall change.
Yes, this chart is colorful and caught my eye, but it’s also worthless.
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Below is another example using similar data where the data visualization is completely ineffective.
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Most Commented Posts
June 24th, 2009 at 10:45 am
Eye catching and useless.
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October 15th, 2009 at 9:18 pm
Totally agree. It is better to divide the chart in to multiple columns.
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October 15th, 2009 at 11:11 pm
Chandoo -
If it’s more than two or three series, clustered columns will be very hard to resolve. However, line charts work very well for this kind of data. Unstacked line charts.
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October 28th, 2009 at 6:47 am
[...] little while back I featured the stacked column chart below in a post that discussed the ineffectiveness of its design. More often than not, a simple multi-series [...]