StatsChat.org.nz"Statistical thinking will one day be as necessary for efficient citizenship as the ability to read and write.”

– H.G. Wells

“We hope that, some day, science reporting may reach the standard of sports reporting”

– Me

xkcd.com

Context

Journalists love totals, but averages, proportions, ratios, or differences are almost always more informative

$40 million/yr divided up over ¼ of working-age New Zealanders is $1/week. Yawn.

Accuracy?

Graphs are the most likely places to find simple errors, but they show up in the text as well

It is the special characteristic of numbers that they have a magnitude as well as an order; numbers measure quantity. Graphics can display the quantitative size of changes as well as their direction. The standard of getting only the direction and not the magnitude right is the philosophy that informs the Pravda School of Ordinal Graphics. There, every chart has a crystal clear direction coupled with fantasy magnitude.

- Edward Tufte

“Co-author of the study, Dr Kyle Burger, from the Oregon Research Institute, told The Daily Telegraph overeating high fat or high sugar foods appeared to change the way the brain responded to the food.”

The study looked at brain activity in people drinking a milkshake compared to a tasteless drink, and found that the milkshake effect was smaller in people who had eaten icecream frequently in past weeks. But it wasn’t smaller in people who had eaten cookies, chocolate, hamburgers, cake, or chips, and there wasn’t any relationship to total dietary fat and sugar.

Bogus Polls

The week after the Crafar farms decision:

• NZ Herald poll: 34% in favour of the decision• Stuff poll: 22% in favour• Campbell Live poll: 3% in favour

The newspaper website polls had about 18000 votes.Margin of sampling error < 1%Accuracy worse than a random sample of ten people

Bogus polls look a bit like real surveys on the outside, but don’t have any of the inner

machinery that you need to make them work.

893042: 800% of readers of the article voted

230%

570%

Looking up dataYou probably aren’t the first person ever to think of this question.

Governments and other organisations spend millions to collect data, put it up on the web, and have it ignored.

“Look at who takes the most sick leave,” said Mr Thompson. “Because you know, once a month they have sick problem. Not all women, but some do. They have children and they have to take leave off.”

Back in reality, while data from around the world show women do take more sick leave than men, the margin is about 2-3 days/year.

Are there more earthquakes when the moon is closer to the earth?

Useful adviceStatistics for fun and/or profit