Friday, September 01, 2006

Lies & Statistics

"There are lies, damn lies, and statistics" said Mark Twain. The world is littered with statistics, and statistically, the average person is bombarded with five statistics a day. Statistics are usually misleading and deliberately distorting, as they are used to demonstrate not random samplings of truth, but trends among a specific area of the population on a specific topic. According to a website on statistics, though, this quote from Mark Twain is accurate: "statistics are often used to lie to the public because most people do not understand how statistics work. The aim of this entry is to acquaint the reader with the basics of statistical analysis and to help them determine when someone is trying to pull a fast one." But then, you must always remember the sage advice of George Carlin, too: "Think about how stupid the average person is; now realise half of them are dumber than that."

In today's News, figures have shown that Tassie has the highest rate of fatal air crashes in the country. Between 1990 and 2004, Tasmania recorded 1.8 fatal accidents per 100,000 landings, above the national average of 0.7 fatalities. The guy in charge of these statistics warns that it should be a wake-up call to all light plane pilots.

Except that Tasmania only has a population of half a million or so people, and the rest of Australia has 20 million. Where a busy Sydney airport might have 100,000 lands per year, we'd be lucky to have 100,000 landings per decade! As everything in Tassie is so easily within driving distance (maximum 4 hour drive from one end of the state to the other) that small planes aren't a big thing here. Even our major airports, like Devonport, only have 3 or 4 small planes hanging around. Ask any Tasmanian when the last air fatality in Tasmania was and the answer will probably be, "Have we ever had one?"

But of course we have had one or two tragic accidents. And those have blown out our statistical bubble so that for the next 20 years at least, we'll be higher than the National Average, even assuming no-one else gets killed.

The lesson? Statistics can say anything at all. Use your brain.

ABC News Tasmanian Air Crashes

1 comment:

Mike Hobart said...

Nevil Shute once wrote a novel about a light plane crashing in Tasmania. From memory it was titled "The Rainbow and the Rose".