“When you have mastered numbers, you will in fact no longer be reading numbers, any more than you read words when reading books. You will be reading meanings.” – W. E. B. Du Bois, Afro-American activist and writer
It’s often good to quote numbers in your presentation. They provide powerful means to support the dialog you’re conducting with your audience. But, beware: figures don’t always speak for themselves. In science, naked numbers are numbers without units. Any scientist or economist will tell you that numbers without labels and charts without legends are meaningless and worthless. How would you feel about being offered a salary of “25”, not knowing if you’ll get 25 euros, 25 cents, or 25 peanuts for your work? per hour, per day, or per week?
Also in my job as a strategist and marketer, I’m frequently confronted with naked numbers, industry analyst reports that contradict each other, and quantitative claims that don’t seem to make any sense at all. As Plato, the Greek philosopher, already said 24 centuries ago: a good decision is based on knowledge and not on numbers. This is exactly why you shouldn’t present naked figures, but complement them by the sources and the formulas you used to obtain them.
And still, even the most unprovable forecasts and improbable measurements may yield good presentation material. Not because of their objective value, but just because some people may agree and others will disagree with them. And that’s exactly the sort of conflict you need to create for fueling a conversation with or between your audience. You’ll get an opportunity to discuss the why and the how, explain the logic behind your story, clarify the assumptions you made, bring additional facts and figures, talk about use cases and customer references, and prove the value of your products and services.
Finally, also remember what I wrote in my “living by numbers” post on this blog: numbers, particularly very large ones, don’t resonate with people until they are presented in an appropriate format. So, it remains essential to use good visualization methods for giving meaning to your figures, and making your audience remember the data you quote.