I think that's mostly a function of many touch screens not being obvious about being touch screens, and some non-touch screens having interfaces that look like

I think that's mostly a function of many touch screens not being obvious about being touch screens, and some non-touch screens having interfaces that look like touch. We have some older machines for getting train tickets and some newer ones. They probably didn't want to scare anybody off, so the interface still looks almost the same. It used to be buttons next to the screen, now it's a touch screen. Of course you see people trying to touch the old ones. There's no signifier on the new ones (except the lack of buttons) that shows that they're different, so without a bit of thinking you don't know which affordances there are.