The Design of Everyday Things

by Donald A. Norman

Consider a bookmark, a deliberately placed signifier of one’s place in reading a book. But the physical nature of books also makes a bookmark an accidental signifier, for its placement also indicates how much of the book remains.

“People don’t want to buy a quarter-inch drill. They want a quarter-inch hole!”

Everyone sometimes acts in a way that seems strange, bizarre, or simply wrong and inappropriate. When we do this, we tend to attribute our behavior to the environment. When we see others do it, we tend to attribute it to their personalities.

Just the opposite attribution, by the way, is made when things go well. When things go right, people credit their own abilities and intelligence. The onlookers do the reverse. When they see things go well for someone else, they sometimes credit the environment, or luck.

The vicious cycle starts: if you fail at something, you think it is your fault. Therefore you think you can’t do that task. As a result, next time you have to do the task, you believe you can’t, so you don’t even try. The result is that you can’t, just as you thought. You’re trapped in a self-fulfilling prophecy.

We need to remove the word failure from our vocabulary, replacing it instead with learning experience. To fail is to learn: we learn more from our failures than from our successes. With success, sure, we are pleased, but we often have no idea why we succeeded. With failure, it is often possible to figure out why, to ensure that it will never happen again.

It is possible to avoid failure, to always be safe. But that is also the route to a dull, uninteresting life.

The idea that a person is at fault when something goes wrong is deeply entrenched in society. That’s why we blame others and even ourselves. Unfortunately, the idea that a person is at fault is imbedded in the legal system. When major accidents occur, official courts of inquiry are set up to assess the blame. More and more often the blame is attributed to “human error.” The person involved can be fined, punished, or fired. Maybe training procedures are revised. The law rests comfortably. But in my experience, human error usually is a result of poor design: it should be called system error. Humans err continually; it is an intrinsic part of our nature. System design should take this into account. Pinning the blame on the person may be a comfortable way to proceed, but why was the system ever designed so that a single act by a single person could cause calamity? Worse, blaming the person without fixing the root, underlying cause does not fix the problem: the same error is likely to be repeated by someone else. I return to the topic of human error in Chapter 5.

One of my self-imposed rules is, “Don’t criticize unless you can do better.” Try to understand how the faulty design might have occurred: try to determine how it could have been done otherwise. Thinking about the causes and possible fixes to bad design should make you better appreciate good design. So, the next time you come across a well-designed object, one that you can use smoothly and effortlessly on the first try, stop and examine it. Consider how well it masters the seven stages of action and the principles of design. Recognize that most of our interactions with products are actually interactions with a complex system: good design requires consideration of the entire system to ensure that the requirements, intentions, and desires at each stage are faithfully understood and respected at all the other stages.

°C = (°F–30) / 2

Why bother? I can estimate the answer in my head with reasonable accuracy, often good enough for the purpose. When I need precision and accuracy, well, that’s what calculators are for.

But why couldn’t the past be in front of us and the future behind? Does that sound strange? Why? We can see what is in front of us, but not what is behind, just as we can remember what happened in the past, but we can’t remember the future. Not only that, but we can remember recent events much more clearly than long-past events, captured neatly by the visual metaphor in which the past lines up before us, the most recent events being the closest so that they are clearly perceived (remembered), with long-past events far in the distance, remembered and perceived with difficulty.

It has fifteen pieces so cleverly constructed that even an adult can put them together.

When I give talks, quite often my first demonstration needs no preparation. I can count on the light switches of the room or auditorium to be unmanageable. “Lights, please,” someone will say. Then fumble, fumble, fumble. Who knows where the switches are and which lights they control? The lights seem to work smoothly only when a technician is hired to sit in a control room somewhere, turning them on and off.

An interlock forces operations to take place in proper sequence.

A lock-in keeps an operation active, preventing someone from prematurely stopping it.

Whereas a lock-in keeps someone in a space or prevents an action until the desired operations have been done, a lockout prevents someone from entering a space that is dangerous, or prevents an event from occurring.

Consistency in design is virtuous. It means that lessons learned with one system transfer readily to others. On the whole, consistency is to be followed. If a new way of doing things is only slightly better than the old, it is better to be consistent. But if there is to be a change, everybody has to change. Mixed systems are confusing to everyone. When a new way of doing things is vastly superior to another, then the merits of change outweigh the difficulty of change. Just because something is different does not mean it is bad. If we only kept to the old, we could never improve.

Yes, these new faucets are beautiful. Sleek, elegant, prize winning. Unusable. They solved one set of problems only to create yet another. The mapping problems now predominate.

The Japanese have long followed a procedure for getting at root causes that they call the “Five Whys,” originally developed by Sakichi Toyoda and used by the Toyota Motor Company as part of the Toyota Production System for improving quality. Today it is widely deployed. Basically, it means that when searching for the reason, even after you have found one, do not stop: ask why that was the case. And then ask why again. Keep asking until you have uncovered the true underlying causes. Does it take exactly five? No, but calling the procedure “Five Whys” emphasizes the need to keep going even after a reason has been found.

We can’t fix problems unless people admit they exist. When we blame people, it is then difficult to convince organizations to restructure the design to eliminate these problems. After all, if a person is at fault, replace the person. But seldom is this the case: usually the system, the procedures, and social pressures have led to the problems, and the problems won’t be fixed without addressing all of these factors.

There is a lot of pressure to push ahead with the work even when an outside observer would say it was dangerous to do so. In many industries, if the operators actually obeyed all the procedures, the work would never get done. So we push the boundaries: we stay up far longer than is natural. We try to do too many tasks at the same time. We drive faster than is safe. Most of the time we manage okay. We might even be rewarded and praised for our heroic efforts. But when things go wrong and we fail, then this same behavior is blamed and punished.

The public hears about their mistakes, but not about the far more frequent cases that they got right or about the times they ignored data as not being meaningful—and were correct to do so.

Never underestimate the power of social pressures on behavior, causing otherwise sensible people to do things they know are wrong and possibly dangerous.

In addition, if the divers released the weights and then made it back safely, they could never prove that the release of the weights was necessary, so they would feel embarrassed, creating self-induced social pressure.

James Reason likes to explain this by invoking the metaphor of multiple slices of Swiss cheese, the cheese famous for being riddled with holes (Figure 5.3). If each slice of cheese represents a condition in the task being done, an accident can happen only if holes in all four slices of cheese are lined up just right. In well-designed systems, there can be many equipment failures, many errors, but they will not lead to an accident unless they all line up precisely.

With self-driving cars, I predict that we will have fewer accidents and injuries, but that when there is an accident, it will be huge.

The Double-Diamond Model of Design. Start with an idea, and through the initial design research, expand the thinking to explore the fundamental issues. Only then is it time to converge upon the real, underlying problem. Similarly, use design research tools to explore a wide variety of solutions before converging upon one.

How does the product manager keep the entire team on schedule despite the apparent random and divergent methods of designers? Encourage their free exploration, but hold them to the schedule (and budget) constraints. There is nothing like a firm deadline to get creative minds to reach convergence.

No matter how much time the design team has been allocated, the final results only seem to appear in the last twenty-four hours before the deadline. (It’s like writing: no matter how much time you are given, it’s finished only hours before the deadline.)

In theory, there is no difference between theory and practice. In practice, there is.

The day a product development process starts, it is behind schedule and above budget.

Note that working with these teams is also a challenge. Everyone speaks a different technical language. Each discipline thinks it is the most important part of the process. Quite often, each discipline thinks the others are stupid, that they are making inane requests.

Standardization provides a major breakthrough in usability.

Most companies compare features with their competition to determine where they are weak, so they can strengthen those areas. Wrong, argues Moon. A better strategy is to concentrate on areas where they are stronger and to strengthen them even more. Then focus all marketing and advertisements to point out the strong points. This causes the product to stand out from the mindless herd. As for the weaknesses, ignore the irrelevant ones, says Moon. The lesson is simple: don’t follow blindly; focus on strengths, not weaknesses. If the product has real strengths, it can afford to just be “good enough” in the other areas.

What industries are ready for radical innovation? Try education, transportation, medicine, and housing, all of which are overdue for major transformation.

Without cognitive technologies, will we fall into an equivalent state of ignorance? These fears have long been with us. In ancient Greece, Plato tells us that Socrates complained about the impact of books, arguing that reliance on written material would diminish not only memory but the very need to think, to debate, to learn through discussion. After all, said Socrates, when a person tells you something, you can question the statement, discuss and debate it, thereby enhancing the material and the understanding. With a book, well, what can you do? You can’t argue back.

Now you are on your own. If you are a designer, help fight the battle for usability. If you are a user, then join your voice with those who cry for usable products. Write to manufacturers. Boycott unusable designs. Support good designs by purchasing them, even if it means going out of your way, even if it means spending a bit more. And voice your concerns to the stores that carry the products; manufacturers listen to their customers.

And enjoy yourself. Walk around the world examining the details of design. Learn how to observe. Take pride in the little things that help: think kindly of the person who so thoughtfully put them in. Realize that even details matter, that the designer may have had to fight to include something helpful. If you have difficulties, remember, it’s not your fault: it’s bad design. Give prizes to those who practice good design: send flowers. Jeer those who don’t: send weeds.