Wednesday, September 15, 2010

The 60,000,008-year-old dinosaur

Don't you just hate rearranging the bookshelves? Now I can't find my copy of "How to Lie with Statistics," but I think that's where the anecdote about the dinosaur comes from, give or take a few tens of millions of years.

Anyway. Teacher takes tinies to the museum. Tinies enthralled by dinosaur skeleton. Teacher asks guard: "How old is the dinosaur?"

"Sixty million and eight years old."

Teacher, impressed, asks guard how he knows so precisely.

"I was hired eight years ago, and they told me it was 60 million years old."

That's the category of hed we have here, and it illustrates a basic principle of journalism arithmetic. The sum of a guess and a number is not a number; it's a guess. The sum of an estimate, a guess and three or four numbers is still not a number; it's a guess too. When you see a lede on the order of:

Seven business expansions in metro Detroit that will create 938 jobs directly were approved for state tax credits Tuesday by the Michigan Economic Growth Authority (MEGA).

... your first order of business is to add up everything that follows and see if you're dealing with a real number or not. Let's see:

"An estimated 280 jobs"

"Up to 288 direct jobs"
"87 direct jobs"
"103 new jobs"
"38 direct new jobs expected"
"67 direct new jobs"
"75 new direct jobs"

You can't take three from two, two is less than three, so you look at the four in the -- very good! The answer isn't "938." It's "more than 900" or some other such approximation, because the sum of "estimated," "up to" and "expected" is ... a guess!

That's an error of omission -- the hed writer repeats the reporter's error, rather than challenging it. The lede says that "business expansions" will create the jobs.* The hed says it's the tax credits. I think the former is more likely. That's a sin of commission.

I'm generally anti-conspiracy-theory by nature, and in the great battle between Media Bias and Media Dumb, my money is usually on Dumb. But if (based on that hed) someone wanted to accuse the paper of distorting the news by way of propagandizing for the economic development office, I'd have a hard time demonstrating otherwise.

* I can take a good guess at what "direct jobs" means, but that too would be a guess. I don't know, I kind of like it when stories spell out what their terms of art mean, and I'm too tired to put up with much "everybody knows what that means." Grr.



Anonymous Nick said...

Good piece.

I'd just like to add that a 60 million year old dinosaur skeleton would be unlikely to entrall tinies because dinosaurs (apart from some birds) became extinct about 64.5 million years ago. (Or 64,497,990 BC. ;-) )

7:53 AM, September 16, 2010  
Blogger fev said...

Sorry. I got my copy of HTLwS in the used-textbook section. The copyright date is 5 million BC.

9:44 AM, September 16, 2010  
Anonymous Mark P said...

60,000,008 million is a lot of millions. In fact, it adds up to around 60 trillion.

11:29 AM, September 16, 2010  
Blogger fev said...

Erk. Hed now fixed to conform with, erm, reality. (No, wait. That'd be "6,000-year-old dinosaur.")

On the bright side, it didn't say "$60,000,000-million-dollar dinosaur."

11:36 AM, September 16, 2010  

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