In Verizon’s post, “A Comparison of [Verizon’s] DBIR with UK breach report,” we see:
Quick: which is larger, the grey slice on top, or the grey slice on the bottom? And ought grey be used for “sophisticated” or “moderate”?
I’m confident that both organizations are focused on accurate reporting. I am optimistic that this small example in the utlity of pie charts will inform report writers. The report writers and their graphics departments, loving their customers, will move to bar charts to help them compare numbers between sources.
I’m confident that not using pie charts is a best practice.
Elsewhere: “The only time it makes sense to use a pie chart.”
And elsewhere: “The Visual Display of Quantitative Information, 2nd edition“