Design: A Matter of Life and Death

Magnificent Publications is often asked to create publications that present data clearly and effectively. Over the next few weeks, we’ll be discussing some of the classic guidelines on the subject from a leading authority on data presentation, Edward Tufte.

Tufte describes his third book, Visual Explanations, as being about:

…pictures of verbs, the representation of mechanism and motion, of process and dynamics, of causes and effects, of explanation and narrative.

As he points out, these are the types of graphics used to make decisions. And in one of his best-known discussions, he examines how poor graphic design contributed to the tragically mistaken decision not to delay the launch of the Challenger space shuttle in 1986.

The problem, essentially, was that cold temperatures caused critical rubber O-ring seals on the main booster to become brittle and inelastic. When these leaked during the launch, the rocket was doomed. In trying to communicate this risk to their superiors, NASA engineers prepared the following two graphics, among others.

He identifies a number of key problems:

• The crosshatching or stippling patterns presented in the legend don’t darken in order as the damage they are meant to convey gets more severe. The letter code only worsens the confusion.
• The legend appears only on the first graphic, not the second. Since these were shown in sequence, on an overhead projector, the audience had to remember what all these little codes meant, a near-impossible task.
• All those rocket outlines constitute “visual noise.”
• Turning the numbers sideways and squashing them against the rocket outlines makes them harder to read.
• The launches are presented in historical order instead of being arranged according to launch temperature, the critical variable the engineers were trying to highlight.

While most decisions don’t carry the life-or-death weight of the Challenger launch, the principle is valid in any situation: proper visual presentation can mean the difference between a convincing case and a confusing one.

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