What Makes a Number Good?
Consider the number 9.
It’s a great number, the last of the single-digits. And it’s versatile: Turn it upside down and you get yourself a 6.
Then there’s 8: Two circles carefully stacked one on top of the other. How about 4? Doesn’t it remind you of someone balancing in tree pose in yoga? No?
Repeating digits—11, say, or 77—have a different sort of charm, like identical twins. Numbers that you get when you multiply a number by itself, like 49 (7x7) or 81 (9x9), have a mysterious depth to them.
It may seem silly to look at numbers like this, but in fact, some folks are so jumpy around numbers that they start to do something very similar—they treat the number as a thing unto itself and don’t stop to put it in context and think about what it means.
“We scored in the 85th percentile!” a med-surg team might trumpet.
“Hey, not bad!” you might respond—our years in school having conditioned us to think 85th percentile sounds about like a B grade.
But what if the 10 other med-surg teams in your area all ranked between the 97th and 99th percentiles? Or what if they all were down in the 40th percentile? In either case, the first team’s rank in the 85th percentile looks entirely different.
It also will tell a different story if you know that the previous quarter, the team had ranked in the 83rd percentile or in the 87th. Is the team improving or backsliding?
And what do those numbers say about the care delivered? What will a neurosurgery team’s 85th percentile ranking mean to its patients?
“We increased our outreach by 50 percent!” can sound great—but can also be misleading. What was the starting point? It may have been so low that even after increasing by 50 percent, there’s still a long way to go to reach the average.
Let’s say you’re looking at wait times in a pharmacy. If the original wait was five minutes and it’s decreased by 50 percent, and is now two and a half minutes, that tells one story. If the original wait was 20 minutes and it’s now down to 10, that tells a different story.
And that’s the point: Numbers, like words, tell stories. Numbers provide a powerful way to compare and contrast conditions, to show what’s changed (or changing)—the starting point of a story.
Bombarded as we are by data, it’s hard not to wish sometimes for a language that would limit our endless quest to quantify. In some aboriginal societies, after all, there are words that mean “one,” “two,” “few” and “many”—and that’s the end of the line for numbers.
Since we don’t have that simplicity, take a look at “How I Learned to Stop Worrying and Love the Data.”