It's largely a matter of asking the right questions, according to this excerpt from the new Data Journalism Handbook. An example: Are there lurking variables in a study linking tea consumption to better health? "In most countries, tea is a beverage for the health-conscious upper classes. If researchers don’t control for lifestyle factors in tea studies, they tell us nothing more than 'rich people are healthier — and they probably drink tea.'"
July 2, 2012