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Data reporting @ Cronkite

Numbers in the newsroom

Statistics are people with the tears washed off

- Paul Brodeur

Jo Craven McGinty, then of The New York Times, used simple rates and ratios to discover that a 6-story brick New Jersey hospital was the most expensive in the nation. In 2012, Bayonne Medical Center “charged the highest amounts in the country for nearly one-quarter of the most common hospital treatments,” the Times story said.

To do this story, McGinty only needed to know the volume of the procedures reported by the government and the total amount each hospital charged. Dividing those to find an average price, then ranking the most common procedures, led to this surprising result.

  1. Why numbers?
  2. Overcoming your fear of math
  3. Put math in its place
  4. Reading and viewing
    1. Simple Census stories
  5. How high school algebra won a Pulitzer Prize
  6. Exercises

Why numbers?

Using averages, percentages and percent change is the bread and butter of data journalism, leading to stories ranging from home price comparisons to school reports and crime trends. It may have been charming at one time for reporters to announce that they didn’t “do” math, but no longer. Instead, it is now an announcement that the reporter can only do some of the job. You will never be able to tackle complicated, in-depth stories without reviewing basic math.

The good news is that most of the math and statistics you need in a newsroom isn’t nearly as difficult as high school algebra. You learned it somewhere around the 4th grade. You then had a decade to forget it before deciding you didn’t like math. But mastering this most basic arithmetic again is a requirement in the modern age.

In working with typical newsroom math, you will need to learn how to:

  • Overcome your fear of numbers
  • Integrate numbers into your reporting
  • Calculate change in a list of items
  • Use different types of averages as summaries of a list of items.

This tutorial has some general tips for dealing with numbers and resources for going further. The common arithmetic you need is covered in the Excel module on formulas.

Overcoming your fear of math

When we learned to read, we got used to the idea that 26 letters in American English could be assembled into units that we understand without thinking – words, sentences, paragraphs and books. We never got the same comfort level with 10 digits, and neither did our audience.

Think of your own reaction to seeing a page of words. Now imagine it as a page of numbers. Seasick yet?

Instead, picture the number “five”. It’s easy. It might be fingers or toe or it might be one team on a basketball court. But it’s simple to understand.

Now picture the number 275 million. It’s hard. Unfortunately, 275 billion isn’t much harder, even though it’s magnitudes larger. (Remember this: 1 million seconds goes by in about 11 days. 1 billion seconds goes by longer than you’ve probably been alive, or more than 35 years.)

So the easiest way to get used to some numbers is to learn ways to cut them down to size, by calculating rates, ratios, percentages and rounding off.

This video will give you a more in-depth pep talk on getting used to numbers.

Put math in its place

For journalists, numbers – or facts – make up the third leg of a stool supported by human stories or anecdotes , and smart or insightful insight from sources. They serve us in three ways:

  • As summaries. Almost by definition, a number counts something, averages something, or otherwise summarizes something. Sometimes, it does a good job, as in the average height of Americans. Sometimes it does a terrible job, as in the average income of Americans. Try to find summaries that accurately characterize the real world.

  • As opinions. Sometimes it’s an opinion derived after years of impartial study. Sometimes it’s an opinion tinged with partisan or selective choices of facts. Use them accordingly.

  • As guesses. Sometimes it’s a good guess, sometimes it’s an off-the-cuff guess. And sometimes it’s a hopeful guess. But even the most accurate of numbers can be guesses, such as the 2017 election in Virginia that swung the state legislature by a single vote in Newport News. If there are slight differences between numbers, maybe they’re not worth writing about.

Once you find the humanity in your numbers, by cutting them down to size and relegating them to their proper role, you’ll find yourself less fearful. You’ll be able to characterize what you’ve learned rather than numb your readers with every number in your notebook. You may even find that finding facts on your own is fun.

Reading and viewing

  • Dealing with the margin of error in surveys and polls, from the Journalists’ Resource at Nieman. (link TK)

Simple Census stories

These stories came out when the 2018 estimates of population were released by the Census, depending just on some smart re-ordering and percent change calculations. It’s an easy way to get practice at basic math.

How high school algebra won a Pulitzer Prize

If you were at all paying attention in pre-college science classes, you have probably seen this equation:

d = rt or distance = rate*time

In English, that says we can know how far something has travelled if we know how fast it’s going and for how long. If we multiply the rate by the time, we’ll get the distance.

If you remember just a bit about algebra, you know we can move these things around. If we know two of them, we can figure out the third. So, for instance, if we know the distance and we know the time, we can use algebra to divide the distance by the time to get the rate.

d/t = r or distance/time = rate

In 2012, the South Florida Sun Sentinel found a story in this formula.

People were dying on South Florida tollways in terrible car accidents. What made these different from other car fatal car accidents that happen every day in the US? Police officers driving way too fast were causing them.

But do police regularly speed on tollways or were there just a few random and fatal exceptions?

Thanks to Florida’s public records laws, the Sun Sentinel got records from the toll transponders in police cars in south Florida. The transponders recorded when a car went through a given place. And then it would do it again. And again.

Given that those places are fixed – they’re toll plazas – and they had the time it took to go from one toll plaza to another, they had the distance and the time.

It took high school algebra to find how fast police officers were driving. And the results were shocking.

Twenty percent of police officers had exceeded 90 miles per hour on toll roads. In a 13-month period, officers drove between 90 and 110 mph more than 5,000 times. And these were just instances found on toll roads. Not all roads have tolls.

The story was a stunning find, and the newspaper documented case after case of police officers violating the law and escaping punishment. And, in 2013, they won the Pulitzer Prize for Public Service.

All with simple high school algebra.

Exercises

  • Imagine that someone gave you $1 million and you could spend it on anything you want. Write down a list of things that would add up to about that amount. That should be easy. Now, imagine someone gave you $1 billion and you could spend it on whatever you want, but anything left over after a year had to be returned. How would you spend it? (You can give away money, but it can’t be more than 50% of a charity’s annual revenues. So you can’t give 10 $100 million gifts!) See how far you get trying to spend it. A few homes, a few yachts, a few student loan repayments? You’ve hardly gotten started.

  • In class: Create a spreadsheet with basic numeric information about your school, such as enrollment this year and last; graduation rates; and tuition. Use basic math to show change, percent change and averages.

  • Imagine it is Jan. 1, 2018 and you are tasked with writing the annual weather story, summarizing the high and low points of the previous year. Using this daily summary of temperatures, rain and wind for Phoenix, try to find three interesting facts for your story. If you want to download your own data from NOAA, choose “Local Climatalogical Data,” and keep only the rows that refer to “SOD,” or “Summary of Day”.

  • Download the population estimates for the nation and calculate percent changes, percent of total, actual change and any other basic stats. Now find a story.

– Sarah Cohen and Matt Waite, Updated August 2019