If you want to make sense of your data you need at least some rudimentary data visualization skills. By “data visualization skills” I don’t mean “to be able to make a chart in Excel”. You must have a deeper understanding of what charts should be used and when, why some many formatting options serve a functional purpose (not an aesthetic one) and even be able to decide that a chart, any chart, is not the best tool in a specific context.

I don’t have a well-rounded data visualization theory. Some general principles seem obvious to me, and from there you can derive a set of “best practices”. But, given the low level of graphic literacy among managers and business users, I am not sure if a radical change (removing pie charts, for example) is the best option.