“Numerical quantities focus on expected values, graphical summaries on unexpected values.”
Communicating data is sharing comparisons, and comparisons are examinations of relative amounts. We make comparisons all day long, without consciously deciding to do so. We love to explore how things are similar or how they are different. Whether we discover something unexpected or confirm a long-held belief, we walk away with a satisfying feeling of knowing.
But we can be highly skeptical of comparisons that others communicate to us. “Our product is better than our competitor’s.” “The economy has gotten worse since my opponent took office.” We’re exposed to comparisons such as these constantly, so it’s natural for us to be wary of them. Some comparisons are definitely odious.
What does this mean when it comes to communicating data? The onus is on the communicator to convey the message accurately and effectively, in order to earn the trust and attention of the target audience. It starts with understanding the nature of the comparison to be made.
Comparisons can include multiple layers, but at their core they always reduce to either how much or how many.
How much involves noncountable nouns like revenue or measurements:
“How much money did we earn this past quarter?”
“How much carbon dioxide is in the atmosphere?”
How many involves countable nouns like people or distinct events:
“How many customers do we have?”
“How many goals did players score this season?” ...