The Data Detective: Ten Easy Rules to Make Sense of Statistics

by Tim Harford

Michael Blastland, co-creator of More or Less, imagines looking at two sheep in a field. How many sheep in the field? Two, of course. Except that one of the sheep isn’t a sheep, it’s a lamb. And the other sheep is heavily pregnant—in fact, she’s in labor, about to give birth at any moment. How many sheep again? One? Two? Two and a half? Counting to three just got difficult.

As the saying goes, extraordinary claims require extraordinary evidence.