The Power of Small Data: Illuminate numbers with meaningful comparisons

Published on
May 2, 2016

Two dozen cases of Ebola virus have been treated in Europe and the United States.

Although measles is preventable with a vaccine, 17 people die from it every hour worldwide.

Nearly 22 percent of Hispanics ages 2 to 19 are considered obese.

You read all those numbers and probably have two questions. 1) Is that true? And 2) Is that bad or good?

I can’t vouch for the veracity of all the statements above, but they all came from recent news stories.

The reason you likely have those two questions is that I have presented these data tidbits without any meaningful comparisons or context. I remember for one project trying to figure out how many swimming pools could be filled up with all the sewage that was regularly dumped into the Pacific Ocean. But I’m not even talking about going to that level of metaphor. I’m talking about simply taking the time to tell your audience 1) Whether they should believe you, and 2) Whether what you are telling them should alarm them, reassure them, or simply pique their curiosity.

Sammy Caiola at The Sacramento Bee spent some time looking at data on the number of physicians in California and about insurance rates in 2015. She was trying to figure out whether the Affordable Care Act had been good or bad for patients in rural areas. She came up with a counter-intuitive finding. Even though more people had signed up for Medi-Cal, the state’s version of Medicaid, this made it even harder for patients to see doctors in rural areas. Why? The math is quite simple. Patient counts go up as Medicaid expands. But doctor counts stay the same. That means more patients are competing for time with the same number of doctors. Caiola explained the resulting imbalance simply and effectively:

State data show about 2.7 million patients have enrolled in Medi-Cal since 2014, and that influx has shrunk the ranks of the state’s uninsured and slowed the rise of insurance premiums. Yet it’s also exacerbated problems in 214 “doctor deserts” statewide – places with only one physician for every 3,500 people. That compares with one physician for every 1,000 people, on average, statewide, and one for every 1,500 in the Sacramento area. Approximately three-quarters of the so-called deserts are in rural areas of California.

Help your audience understand all the data you are sharing by making comparisons that enlighten. That Ebola statistic I shared at the beginning? That’s 24 cases in both the U.S. and Europe. In the U.S., there have only been two known cases of people being treated for the disease since the most recent outbreak in 2014. And yet the threat of Ebola, and more recently Zika, looms quite large for so many people, especially those in Congress.

Edward Humes, one of the most skilled journalists ever to practice the craft, has just published a new book about transportation reviewed in the latest New York Times Book Review. The reviewer, Mary Roach, takes a comparison from the book to emphasize how easily distracted people are from the real problems right in front of them:

During 2014, Humes notes, inebriates behind the wheel killed 12,000 people in the United States. Ebola? Two.

And just to end on a high note, let’s go underground. Mark Brown at Wired wrote about an emergency effort in London to clear out all the built up fat (from cooking oil mostly) that had been flushed into the sewer system, a frequent culprit in the blockages that caused the types of sewer spills I used to write about in California. Now dig this imagery Brown used:

A team of ‘flushers,’ equipped with full breathing apparatus, shovels and powerful jets have been drafted in to dig out and break up the fat, which is enough to fill up nine double-decker buses. ‘We couldn't even access the sewer as it was blocked by a four-foot wall of solid fat,’ said the company’s sewer flusher Danny Brackley.

Nine double-decker buses roaming the streets of London stacked high with sewer fat. That’s enough to lead anyone to say without a shadow of a doubt: “That’s bad.”

[Photo by Ding Yuin Shan via Flickr.]