What Makes a Design Seem 'Intuitive'? 24Jan05

Jared M. Spool wrote in this articel about an interesting theory. In his research he discovered, that users call an interface "intuitive" if one of the following conditions are met:

• the User looks at the interface and knows how to use it from experience


• the User don't know how to use the interface. But he is unaware that the design is helping him. "The user is being trained, but in a way that seems natural."

He explains the theory with the following example:
"The Hotel Phone

Recently, I stayed in a hotel while visiting an old friend. Wanting to call my friend to warn him of my imminent arrival, I approached the phone in my hotel room and lifted the receiver, ready to make my call. Can you guess what button I pressed first?

Chances are you guessed the ‘9’ button. As adults, we learn at an early age that the ‘9’ button will get us an outside line when using a business or hotel phone system. This becomes part of our current knowledge as we travel from phone system to phone system. ‘9’ becomes intuitive, though it isn’t innate—we had to learn it somewhere along the way.

Of course, for this hotel, you would’ve been wrong. The designers of this phone felt that the ‘8’ button was a much better choice. How unintuitive could they be? Everybody knows ‘9’ is far more intuitive!

Because other people had problems with this, there were little signs all over—on the phone, on the wall, on the receiver—that stated you needed to press ‘8’ to get an outside line. I immediately saw these signs and, without really contemplating the design, pressed ‘8’ and the rest of my friend’s number.

The signs made ‘8’ seem intuitive by training me without my even realizing it. They narrowed the gap quickly and without the distraction often associated with learning new things.

Had the phone used the ‘9’ button, it would’ve met condition #1. However, since it had the signs for the ‘8’ button and they worked unobtrusively, it met condition #2."

related link:
User Interface Engineering