Image: Skinny-leg jeans. Not my legs. Or my jeans. © Claude Truong-Ngoc CC BY-SA 3.0, via wikimedia.org
I went shopping for jeans last week, and came home frustrated. (As usual, yes, I’m eventually heading somewhere.) I have calves of considerable circumference, and the fashion in men’s jeans now seems to be for a very narrow-cut leg. I took pair after pair into the fitting room, only to discover I couldn’t even force my leg through the available hole. I know, hold the presses – I’m old and I don’t like today’s fashion; and while we’re at it, all you kids get off my lawn!
But from my (admittedly weird) utilitarian point of view, I just don’t understand skinny-leg jeans. Here’s why. If you make a pair of skinny-leg jeans, they can be used by a skinny-leg person, but not – not even a little bit – by a non-skinny-leg person. If you make a pair of wide-leg jeans, they accommodate both. There’s a fundamental asymmetry in usefulness that makes it seem obvious, to me, how jeans ought to be sewn.
The same asymmetry is why I teach students to report exact P-values, not just “P<0.05” or “P>0.05”.* Continue reading