Design of Everyday Things - Norman, Don [17]
I recently spent six months at the Applied Psychology Unit in Cambridge, England. Just before I arrived the British Telecom Company had installed a new telephone system. It had lots and lots of features. The telephone instrument itself was unremarkable (figure 1.11). It was the standard twelve-button, push-button phone, except that it had an extra key labeled “R” off on the side. (I never did find out what that key did.)
The telephone system was a standing joke. Nobody could use all the features. One person even started a small research project to record people’s confusions. Another person wrote a small “expert systems” computer program, one of the new toys of the field of artificial intelligence; the program can reason through complex situations. If you wanted to use the phone system, perhaps to make a conference call among three people, you asked the expert system and it would explain how to do it. So, you’re on the line with someone and you need to add a third person to the call. First turn on your computer. Then load the expert system. After three or four minutes (needed for loading the program), type in what you want to accomplish. Eventually the computer will tell you what to do—if you can remember why you want to do it, and if the person on the other end of the line is still around. But, as it happens, using the expert system is a lot easier than reading and understanding the manual provided with the telephone (figure 1.12).
1.11 British Telecom Telephone. This was in my office at the Applied Psychology Unit in Cambridge, England. It certainly looks simple, doesn’t it?
1.12 Two Ways to Use Hold on Modem Telephones. Illustration A (below left) is the instruction manual page for British Telecom. The procedure seems especially complicated, with three 3-digit codes to be learned: 681, 682, and 683. Illustration B (below right) shows the equivalent instructions for the Ericsson Single Line Analog Telephone installed at the University of California, San Diego. I find the second set of instructions easier to understand, but one must still dial an arbitrary digit: 8 in this case.
Why is that telephone system so hard to understand? Nothing in it is conceptually difficult. Each of the operations is actually quite simple. A few digits to dial, that’s all. The telephone doesn’t even look complicated. There are only fifteen controls: the usual twelve buttons—ten labeled o through 9, #, and *—plus the handset itself, the handset button, and the mysterious “R” button. All except the “R” are the everyday parts of a normal modem telephone. Why was the system so difficult?
A designer who works for a telephone company told me the following story:
“I was involved in designing the faceplate of some of those new multifunction phones, some of which have buttons labeled “R.” The “R” button is kind of a vestigial feature. It is very hard to remove features of a newly designed product that had existed in an earlier version. It’s kind of like physical evolution. If a feature is in the genome, and if that feature is not associated with any negativity (i.e., no customers gripe about it), then the feature hangs on for generations.
“It is interesting that things like the “R” button are largely determined through examples. Somebody asks, ‘What is the “R” button used for?’ and the answer is to give an example: ‘You can push “R” to access loudspeaker paging.’ If nobody can think of an example, the feature is dropped. Designers are pretty bright people, however. They can come up with a plausible-sounding example for almost anything. Hence, you get features, many many features, and these features hang on for a long time. The end result is complex interfaces for essentially simple things.”6
As I pondered this problem, I decided it would make sense to compare the phone system with something that was of equal or greater complexity but easier to use. So let us temporarily leave the difficult telephone system and take a look at my automobile. I bought a car in Europe. When I