In an earlier article, we talked about cognitive load and how that impacts the items we create. Cognitive load is also fundamental to presenting data in general.
Why People Struggle to Understand Large Numbers
Our capacity to take in new information is finite. Put another way, the capacity of humanity to perceive things is currently limited. When that capacity is exceeded, perceptual errors take place.
This rule applies to multiple fields. For example, many have heard of the Dunbar number, which is the average maximum number of quality relationships someone can maintain with others at once. [1] It becomes difficult to form and maintain deep connections beyond the limits of one's Dunbar number.
Another field in which the perceptual capacity of people can lead to errors relates to very large numbers. This effect has been described in popular culture by the quote: "A single death is a tragedy; a million deaths is a statistic."
According to Professor Elizabeth Toomarian at Stanford University, humans were designed to track changes in their immediate environment essential for their survival, like how many berries are on a bush. [2] It is only recently that humans have begun asking themselves to understand quantities not relevant to their immediate environment, like how big the national debt is. As a result, when we begin tracking numbers of things above four or five, we fall back into estimation and maybe even use different brain systems. For example, we rarely count the number of people standing in line at the grocery store. Instead, we estimate the different lengths of lines and choose the one we like best.
As Spencer Greensburg puts it, "...When we're talking about millions of things our ability to visualize completely fails." [3] Our modern obsession with numbers was simply not relevant to our ancestors. Some languages do not even have exact numerical quantities, instead only differentiating between "a little" and "more."
How To Communicate Large Numbers
While it may be daunting to try to communicate large numbers given our limited ability to understand them, there are ways to more effectively communicate large numbers.
When you are presenting big numbers, visualization is key. It comes back to the estimation piece Professor Toomarian wrote about. When we look at the number of people in line in the grocery store, we rarely count them. Rather, we compare the relative lengths of the lines and estimate. These visual systems used in the grocery store also can be used in presenting more abstract data to make it more interpretable.
Another way of mitigating the effects of very large numbers is converting the units of measurement. Spencer Greensburg points out that understanding the U.S. national debt figure of $17 trillion is impossible. However, when we look at $17 trillion divided by the number of people in the USA - $54,000 per person is a much easier amount to conceptualize.
[2] Why your brain struggles with big numbers - NPR
[3] How to Comprehend Incomprehensibly Large Numbers - Gizmodo
