How to pick the right data chart

PowerPoint offers a vaste number of options for designing a data chart. Which one should you choose? Here are some of the guidelines I use:
  • A ranking by size: horizontal bar
  • Development over time with a handful of data points: column, if there are many data points a (fat) line
  • Decomposition of something in its parts: a waterfall (see a post on how to make waterfalls charts), waterfalls also work great to visualize 1 year of a Profit & Loss statement
  • Showing something as a % of the total: a pie chart if it is one year/period, a series of 100% columns if it is a trend over time.
Data has multiple messages. In the analysis phase of your work, you need to study all of them. But when you are ready to present conclusions, you pick the one and only message that is worth emphasizing. If you cannot settle on one, make 2 charts and present them quickly after each other: the market grew [click], our market share increased.

If things get really complex, for example when there are 3 or more factors driving change going into difference directions, you might have to resort to a source-of-change waterfall chart, followed by a data chart that highlights each of the trends individually.

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