The Design of Everyday Things

by Don Norman

  A STANDARD THAT TOOK SO LONG, TECHNOLOGY OVERRAN IT

  I myself participated at the very end of the incredibly long, complex political process of establishing the US standards for high-definition television. In the 1970s, the Japanese developed a national television system that had much higher resolution than the standards then in use: they called it “high-definition television.”

  In 1995, two decades later, the television industry in the United States proposed its own high-definition TV standard (HDTV) to the Federal Communications Commission (FCC). But the computer industry pointed out that the proposals were not compatible with the way that computers displayed images, so the FCC objected to the proposed standards. Apple mobilized other members of the industry and, as vice president of advanced technology, I was selected to be the spokesperson for Apple. (In the following description, ignore the jargon—it doesn’t matter.) The TV industry proposed a wide variety of permissible formats, including ones with rectangular pixels and interlaced scan. Because of the technical limitations in the 1990s, it was suggested that the highest-quality picture have 1,080 interlaced lines (1080i). We wanted only progressive scan, so we insisted upon 720 lines, progressively displayed (720p), arguing that the progressive nature of the scan made up for the lesser number of lines.

  The battle was heated. The FCC told all the competing parties to lock themselves into a room and not to come out until they had reached agreement. As a result, I spent many hours in lawyers’ offices. We ended up with a crazy agreement that recognized multiple variations of the standard, with resolutions of 480i and 480p (called standard definition), 720p and 1080i (called high-definition), and two different aspect ratios for the screens (the ratio of width to height), 4:3 (= 1.3)—the old standard—and 16:9 (= 1.8)—the new standard. In addition, a large number of frame rates were supported (basically, how many times per second the image was transmitted). Yes, it was a standard, or more accurately a large number of standards. In fact, one of the allowed methods of transmission was to use any method (as long as it carried its own specifications along with the signal). It was a mess, but we did reach agreement. After the standard was made official in 1996, it took roughly ten more years for HDTV to become accepted, helped, finally, by a new generation of television displays that were large, thin, and inexpensive. The whole process took roughly thirty-five years from the first broadcasts by the Japanese.

  Was it worth the fight? Yes and no. In the thirty-five years that it took to reach the standard, the technology continued to evolve, so the resulting standard was far superior to the first one proposed so many years before. Moreover, the HDTV of today is a huge improvement over what we had before (now called “standard definition”). But the minutiae of details that were the focus of the fight between the computer and TV companies was silly. My technical experts continually tried to demonstrate to me the superiority of 720p images over 1080i, but it took me hours of viewing special scenes under expert guidance to see the deficiencies of the interlaced images (the differences only show up with complex moving images). So why did we care?

  Television displays and compression techniques have improved so much that interlacing is no longer needed. Images at 1080p, once thought to be impossible, are now commonplace. Sophisticated algorithms and high-speed processors make it possible to transform one standard into another; even rectangular pixels are no longer a problem.

  As I write these words, the main problem is the discrepancy in aspect ratios. Movies come in many different aspect ratios (none of them the new standard) so when TV screens show movies, they either have to cut off part of the image or leave parts of the screen black. Why was the HDTV aspect ratio set at 16:9 (or 1.8) if no movies used that ratio? Because engineers liked it: square the old aspect ratio of 4:3 and you get the new one, 16:9.

  Today we are about to embark on yet another standards fight over TV. First, there is three-dimensional TV: 3-D. Then there are proposals for ultra-high definition: 2,160 lines (and a doubling of the horizontal resolution as well): four times the resolution of our best TV today (1080p). One company wants eight times the resolution, and one is proposing an aspect ratio of 21:9 (= 2.3). I have seen these images and they are marvelous, although they only matter with large screens (at least 60 inches, or 1.5 meters, in diagonal length), and when the viewer is close to the display.

  Standards can take so long to be established that by the time they do come into wide practice, they can be irrelevant. Nonetheless, standards are necessary. They simplify our lives and make it possible for different brands of equipment to work together in harmony.

  A STANDARD THAT NEVER CAUGHT ON: DIGITAL TIME

  Standardize and you simplify lives: everyone learns the system only once. But don’t standardize too soon; you may be locked into a primitive technology, or you may have introduced rules that turn out to be grossly inefficient, even error-inducing. Standardize too late, and there may already be so many ways of doing things that no international standard can be agreed on. If there is agreement on an old-fashioned technology, it may be too expensive for everyone to change to the new standard. The metric system is a good example: it is a far simpler and more usable scheme for representing distance, weight, volume, and temperature than the older English system of feet, pounds, seconds, and degrees on the Fahrenheit scale. But industrial nations with a heavy commitment to the old measurement standard claim they cannot afford the massive costs and confusion of conversion. So we are stuck with two standards, at least for a few more decades.

  Would you consider changing how we specify time? The current system is arbitrary. The day is divided into twenty-four rather arbitrary but standard units—hours. But we tell time in units of twelve, not twenty-four, so there have to be two cycles of twelve hours each, plus the special convention of a.m. and p.m. so we know which cycle we are talking about. Then we divide each hour into sixty minutes and each minute into sixty seconds.

  What if we switched to metric divisions: seconds divided into tenths, milliseconds, and microseconds? We would have days, millidays, and microdays. There would have to be a new hour, minute, and second: call them the digital hour, the digital minute, and the digital second. It would be easy: ten digital hours to the day, one hundred digital minutes to the digital hour, one hundred digital seconds to the digital minute.

  Each digital hour would last exactly 2.4 times an old hour: 144 old minutes. So the old one-hour period of the schoolroom or television program would be replaced with a half-digital hour period, or 50 digital minutes—only 20 percent longer than the current hour. We could adapt to the differences in durations with relative ease.

  What do I think of it? I much prefer it. After all, the decimal system, the basis of most of the world’s use of numbers and arithmetic, uses base 10 arithmetic and, as a result, arithmetic operations are much simpler in the metric system. Many societies have used other systems, 12 and 60 being common. Hence twelve for the number of items in a dozen, inches in a foot, hours in a day, and months in a year; sixty for the number of seconds in a minute, seconds in a degree, and minutes in an hour.

  The French proposed that time be made into a decimal system in 1792, during the French Revolution, when the major shift to the metric system took place. The metric system for weights and lengths took hold, but not for time. Decimal time was used long enough for decimal clocks to be manufactured, but it eventually was discarded. Too bad. It is very difficult to change well-established habits. We still use the QWERTY keyboard, and the United States still measures things in inches and feet, yards and miles, Fahrenheit, ounces, and pounds. The world still measures time in units of 12 and 60, and divides the circle into 360 degrees.

  In 1998, Swatch, the Swiss watch company, made its own attempt to introduce decimal time through what it called “Swatch International Time.” Swatch divided the day into 1,000 “.beats,” each .beat being slightly less than 90 seconds (each .beat corresponds to one digital minute). This system did not use time zones, so people the world over would be in syn
chrony with their watches. This does not simplify the problem of synchronizing scheduled conversations, however, because it would be difficult to get the sun to behave properly. People would still wish to wake up around sunrise, and this would occur at different Swatch times around the world. As a result, even though people would have their watches synchronized, it would still be necessary to know when they woke up, ate, went to and from work, and went to sleep, and these times would vary around the world. It isn’t clear whether Swatch was serious with its proposal or whether it was one huge advertising stunt. After a few years of publicity, during which the company manufactured digital watches that told the time in .beats, it all fizzled away.

  Speaking of standardization, Swatch called its basic time unit a “.beat” with the first character being a period. This nonstandard spelling wreaks havoc on spelling correction systems that aren’t set up to handle words that begin with punctuation marks.

  Deliberately Making Things Difficult

  How can good design (design that is usable and understandable) be balanced with the need for “secrecy” or privacy, or protection? That is, some applications of design involve areas that are sensitive and necessitate strict control over who uses and understands them. Perhaps we don’t want any user-in-the-street to understand enough of a system to compromise its security. Couldn’t it be argued that some things shouldn’t be designed well? Can’t things be left cryptic, so that only those who have clearance, extended education, or whatever, can make use of the system? Sure, we have passwords, keys, and other types of security checks, but this can become wearisome for the privileged user. It appears that if good design is not ignored in some contexts, the purpose for the existence of the system will be nullified. (A computer mail question sent to me by a student, Dina Kurktchi. It is just the right question.)

  In Stapleford, England, I came across a school door that was very difficult to open, requiring simultaneous operation of two latches, one at the very top of the door, the other down low. The latches were difficult to find, to reach, and to use. But the difficulties were deliberate. This was good design. The door was at a school for handicapped children, and the school didn’t want the children to be able to get out to the street without an adult. Only adults were large enough to operate the two latches. Violating the rules of ease of use is just what was needed.

  Most things are intended to be easy to use, but aren’t. But some things are deliberately difficult to use—and ought to be. The number of things that should be difficult to use is surprisingly large:

  •Any door designed to keep people in or out.

  •Security systems, designed so that only authorized people will be able to use them.

  •Dangerous equipment, which should be restricted.

  •Dangerous operations that might lead to death or injury if done accidentally or in error.

  •Secret doors, cabinets, and safes: you don’t want the average person even to know that they are there, let alone to be able to work them.

  •Cases deliberately intended to disrupt the normal routine action (as discussed in Chapter 5). Examples include the acknowledgment required before permanently deleting a file from a computer, safeties on pistols and rifles, and pins in fire extinguishers.

  •Controls that require two simultaneous actions before the system will operate, with the controls separated so that it takes two people to work them, preventing a single person from doing an unauthorized action (used in security systems or safety-critical operations).

  •Cabinets and bottles for medications and dangerous substances deliberately made difficult to open to keep them secure from children.

  •Games, a category in which designers deliberately flout the laws of understandability and usability. Games are meant to be difficult; in some games, part of the challenge is to figure out what is to be done, and how.

  Even where a lack of usability or understandability is deliberate, it is still important to know the rules of understandable and usable design, for two reasons. First, even deliberately difficult designs aren’t entirely difficult. Usually there is one difficult part, designed to keep unauthorized people from using the device; the rest of it should follow the normal principles of good design. Second, even if your job is to make something difficult to do, you need to know how to go about doing it. In this case, the rules are useful, for they state in reverse just how to go about the task. You could systematically violate the rules like this:

  •Hide critical components: make things invisible.

  •Use unnatural mappings for the execution side of the action cycle, so that the relationship of the controls to the things being controlled is inappropriate or haphazard.

  •Make the actions physically difficult to do.

  •Require precise timing and physical manipulation.

  •Do not give any feedback.

  •Use unnatural mappings for the evaluation side of the action cycle, so that system state is difficult to interpret.

  Safety systems pose a special problem in design. Oftentimes, the design feature added to ensure safety eliminates one danger, only to create a secondary one. When workers dig a hole in a street, they must put up barriers to prevent cars and people from falling into the hole. The barriers solve one problem, but they themselves pose another danger, often mitigated by adding signs and flashing lights to warn of the barriers. Emergency doors, lights, and alarms must often be accompanied by warning signs or barriers that control when and how they can be used.

  Design: Developing Technology for People

  Design is a marvelous discipline, bringing together technology and people, business and politics, culture and commerce. The different pressures on design are severe, presenting huge challenges to the designer. At the same time, the designers must always keep foremost in mind that the products are to be used by people. This is what makes design such a rewarding discipline: On the one hand, woefully complex constraints to overcome; on the other hand, the opportunity to develop things that assist and enrich the lives of people, that bring benefits and enjoyment.

  CHAPTER SEVEN

  DESIGN IN THE WORLD OF BUSINESS

  The realities of the world impose severe constraints upon the design of products. Up to now I have described the ideal case, assuming that human-centered design principles could be followed in a vacuum; that is, without attention to the real world of competition, costs, and schedules. Conflicting requirements will come from different sources, all of which are legitimate, all of which need to be resolved. Compromises must be made by all involved.

  Now it is time to examine the concerns outside of human-centered design that affect the development of products. I start with the impact of competitive forces that drive the introduction of extra features, often to excess: the cause of the disease dubbed “featuritis,” whose major symptom is “creeping featurism.” From there, I examine the drivers of change, starting with technological drivers. When new technologies emerge, there is a temptation to develop new products immediately. But the time for radically new products to become successful is measured in years, decades, or in some instances centuries. This causes me to examine the two forms of product innovation relevant to design: incremental (less glamorous, but most common) and radical (most glamorous, but rarely successful).

  I conclude with reflections about the history and future prospects of this book. The first edition of this book has had a long and fruitful life. Twenty-five years is an amazingly long time for a book centered around technology to have remained relevant. If this revised and expanded edition lasts an equally long time, that means fifty years of The Design of Everyday Things. In these next twenty-five years, what new developments will take place? What will be the role of technology in our lives, for the future of books, and what are the moral obligations of the design profession? And finally, for how long will the principles in this book remain relevant? It should be no surprise that I believe they will always be just as relevant as they were twenty-five years ago, just as relevant as they a
re today. Why? The reason is simple. The design of technology to fit human needs and capabilities is determined by the psychology of people. Yes, technologies may change, but people stay the same.

  Competitive Forces

  Today, manufacturers around the world compete with one another. The competitive pressures are severe. After all, there are only a few basic ways by which a manufacturer can compete: three of the most important being price, features, and quality—unfortunately often in that order of importance. Speed is important, lest some other company get ahead in the rush for market presence. These pressures make it difficult to follow the full, iterative process of continual product improvement. Even relatively stable home products, such as automobiles, kitchen appliances, television sets, and computers, face the multiple forces of a competitive market that encourage the introduction of changes without sufficient testing and refinement.

  Here is a simple, real example. I am working with a new startup company, developing an innovative line of cooking equipment. The founders had some unique ideas, pushing the technology of cooking far ahead of anything available for homes. We did numerous field tests, built numerous prototypes, and engaged a world-class industrial designer. We modified the original product concept several times, based on early feedback from potential users and advice from industry experts. But just as we were about to commission the first production of a few hand-tooled working prototypes that could be shown to potential investors and customers (an expensive proposition for the small self-funded company), other companies started displaying similar concepts in the trade shows. What? Did they steal the ideas? No, it’s what is called the Zeitgeist, a German word meaning “spirit of the time.” In other words, the time was ripe, the ideas were “in the air.” The competition emerged even before we had delivered our first product. What is a small, startup company to do? It doesn’t have money to compete with the large companies. It has to modify its ideas to keep ahead of the competition and come up with a demonstration that excites potential customers and wows potential investors and, more importantly, potential distributors of the product. It is the distributors who are the real customers, not the people who eventually buy the product in stores and use it in their homes. The example illustrates the real business pressures on companies: the need for speed, the concern about costs, the competition that may force the company to change its offerings, and the need to satisfy several classes of customers—investors, distributors, and, of course, the people who will actually use the product. Where should the company focus its limited resources? More user studies? Faster development? New, unique features?