I was discussing interface design with a couple of people last week – specifically, gestural or “natural” interfaces and I mentioned the idea of “interface without interface”. It can be described this way: the natural world does not come with instructions – and natural things do not come with buttons to indicate where you must press for an action or where you must look. For instance, an apple does not come with markings on where to bite and a flower has no indication that it must be put up to your nose. These actions either come naturally to animals or they must be learned – nuture.

I think this concept is an important one. It makes for more beautiful objects. We can and should apply such concepts to interface design more often to make for a better experience.

Recently, we’ve seen a great deal of press about touch screen and gestural interfaces. But even these don’t quite highlight this concept because many simply replace a finger for a mouse pointer – and leave all the buttons and scrollbars in a user interface untouched. I think one place you can see this “natural” idea is with documents that have large canvases – maps and web pages. Consider, for instance, how a user can move around a large map with iPhone or with Google Maps online. You simply recenter the canvas by dragging it and moving it around to a more convenient location. Another great example are the gestural controllers built into Toshiba’s SpursEngine. I got to play with it earlier this year at CES. It’s still in the early stages of development, so the experience is a little crude. But the interesting point it makes is that people should be able to interact with machines using gestures they are normally used to (waving hi; holding up a thumbs-up; etc).

One of the best examples of gestures I’ve seen is ShutUp. The use case is specific – but it gets the point of a good gestural interface across quickly. Let’s say you are in a meeting and suddenly your phone that’s sitting on the table starts ringing. The application gives you the ability to silence it by simply flipping it over on its back. It’s a natural gesture – and there was no need to hunt for the “silence call” button.

That’s interface without interface.