The general thought in user interface design is to make the interface (webpage, software, physical device, whatever) be intuitive to the user. In other words, when the user performs an action in the interface, the product should do what the user expects the device to do. For example, if you press a right-facing arrow button on a music player, you expect this should start some music playing.
This is usually presented in absolute terms, where newer iterations of an interface get closer and closer to behaving as users expect. For example, the when the iPhone is rotated to horizontal position, the screen changes orientation as well. That’s fantastic.
But there’s something deeper at play. The users are learning too. Their expectations are getting more sophisticated and build on what they’ve already learned.
I thought of this the other day while contemplating some of the new interface features on my iPod Touch, and contrasting this with how the original iPod was lauded for it’s brutally simple and intuitive interface.
Has Apple discerned deeper truths about our expectations for interfaces, or have we the iPod users been enrolled in a multiyear training program? We’ve been learning about podcasts, about gestures, about tap-and-hold, about push interrupts, and much more.
If the iPod touch of today was shown to users of the original iPod in 2000, they would be incredibly confused.
In fact, users are always locked in an intricate interface-expectation dance with any device.
This works because their are enough users enrolled in this “training program”, and they are happy to help new initiates get up to speed on the interface basics.
Consider another example: even into the late 90’s, most computers manuals came with instructions on how to use a “mouse” and how to click on virtual “buttons” on the screen. You don’t see this anymore, because these skills are now so widely dispersed that any poor sole who doesn’t know them can learn from a colleage or friend.
Facebook with its constant user interface updates is wresting with this learning curve too. I’d wager that the Facebook of today, if launched 6 years ago, would never have become popular because of it’s extreme complexity. But again, there are millions of pupils who have been learning bit by bit along the way, and initiating their friends into the ways of Facebook.
Bottom line: If you are designing an interface for a new type of system, you must start incredibly simple. But if you grow the interface complexity slowly, you can build up a body of experienced users who will help newcomers. Grow too slow and you become stale, grow to slow and you leave your users behind.