Oo, excellent! The site maintainer clearly knows a bit about human factors design, as he uses terms such as "affords" and knows that if a thing needs a sign there's a problem. The book rampling recommends is also full of such nuggets.

I live in a house where, after FIVE YEARS, I'm still flipping the wrong light switch a lot of the time. If I think about it I can get it right, but when I don't think about it it's a toss-up. The issue? Simple placement. Any time there are multiple switches, the switch FARTHEST from a thing controls it. Except one: the storage room. I think the exception is what makes the bad rule unlearnable!