Design, label, and caption diagrams clearly

Of course diagrams can break up text, relieving otherwise uninterrupted, sometimes daunting text columns. But although useful, the passive ability to take up space is the least of their benefits. Among the myriad active roles they perform, charts, graphs, maps, and process drawings can

  • compare numbers
  • plot locations
  • clarify relationships
  • show trends
  • quickly and sometimes dramatically answer questions for the reader

When the situation calls for a diagram, a well-designed one communicates more clearly and memorably than text alone can. It communicates on a different level than words do because it shows, it doesn't just tell. Good writing creates images in readers’ minds; diagrams, like good photos, bring the images into focus. Unlike most photos, diagrams also can bring numbers into focus.

A graph is “a shorthand means of presenting information that would take many more words and numbers to describe. A graph is successful if the pattern, trend, or comparison it presents can be immediately apprehended,” according to Graph Design for the Eye and Mind by Stephen Kosslyn.

When readers see it before text that describes it, a good diagram might provide an overview that draws them into the text to learn more. When they see the diagram after reading, it can deepen understanding by (depending on the situation):

  • adding depth with the visual perspective
  • eliminating wrong impressions
  • improving information recognition and recall

Those ...

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