Book Summary: Making Numbers Count

By Chip Heath and Karla Starr. Available at Barnes & Noble (and elsewhere.)

• Avoid using numbers, if possible
• Provide a yardstick that people are familiar with to compare quantities to (e.g., the Empire State Building, for length).
• Focus on one item or event at a time (e.g., state the number of points scored by a player per game instead of over entire career).
• Describe a representative case study instead of presenting statistics. The presented case could be fictional, in which case it is called a prototype.
• Round aggressively. Prefer simple fractions (people will remember 1/2 longer—and therefore more accurately—than 9/17).
• Use whole numbers if possible. It’s easy for people to understand “1 out of 3” than “33.3%”.
• If you can make a number “human scale”, then your audience will be able to picture it. Example: to give people a sense of the height of Mt. Everest, scale it down to a size we can understand: “If you were the height of a stack of six cards, Mt. Everest would be the height of a 2-story building.”
• To give exceptionally large or small values an emotional kick, give a comparison to a value that you would expect to be a totally different ballpark. For example, compare the size of California’s economy with the size of the world’s largest countries’ economies.
• Make numbers personal to the audience. Tell a story that includes each audience member as a (possibly hypothetical) participant. Example: if presenting the share of income that an average Kenyan spends on food, state how much that would equal scaled to the income of a typical person in the audience.
• Present your numbers with physical demonstrations in the room. Pick people in the room to represent population statistics (“Look to the two people next to you. It is statistically most likely that one of you will die of heart disease”).
• Convert numbers into periods of time. How long would it take to reach X at a rate that the audience can picture?
• To make exceptional numbers pack a stronger emotional punch, present them as a (surprise) encore. Begin by describing the number in a way that makes them sound significant, then add a modification that shows that the number is actually more extreme than the initial description.
• Set up a pattern then break it. Example: present the thickness of the thinnest laptops on the market, then show your company’s new laptop that is half as thin.