Emotional Design

by Donald A. Norman

  How does one discover “unarticulated needs”? Certainly not by asking, not by focus groups, not by surveys or questionnaires. Who would have thought to mention the need for cup holders in a car, or on a stepladder, or on a cleaning machine? After all, coffee drinking doesn’t seem to be a requirement for cleaning any more than for driving in an automobile. It is only after such enhancements are made that everyone believes them to be obvious and necessary. Because most people are unaware of their true needs, discovering them requires careful observations in their natural environment. The trained observer can often spot difficulties and solutions that even the person experiencing them does not consciously recognize. But once an issue has been pointed out, it is easy to tell when you have hit the target. The response of the people who actually use the product is apt to be something like, “Oh, yeah, you’re right, that’s a real pain. Can you solve that? That would be wonderful.”

  After function comes understanding. If you can’t understand a product, you can’t use it—at least not very well. Oh, sure, you could memorize the basic operating steps, but you probably will have to be reminded over and over again what they are. With a good understanding, once an operation is explained, you are apt to say, “Oh, yes, I see,” and from then on require no further explanation or reminding. “Learn once, remember forever,” ought to be the design mantra.

  Without understanding, people have no idea what to do when things go wrong—and things always go wrong. The secret to good understanding is to establish a proper conceptual model. In The Design of Everyday Things, I pointed out that there are three different mental images of any object. First is the image in the head of the designer—call that the “designer’s model.” Then the image that the person using the device has of it and the way it works: call this the “user’s model.” In an ideal world, the designer’s model and the user’s model should be identical and, as a result, the user understands and uses the item properly. Alas, designers don’t talk to the final users; they only specify the product. People form their models entirely from their observations of the product—from its appearance, how it operates, what feedback it provides, and perhaps, any accompanying written material, such as the advertising and manuals. (But most people don’t read the manuals.) I called the image conveyed by the product and written material the “system image.”

  As Figure 3.4 indicates, designers can communicate with the eventual users only through the system image of a product. Thus, a good designer will make sure that the system image of the final design conveys the proper user model. The only way to find this out is through testing: develop early prototypes, then watch as people try to use them. What is something with a good system image? Almost any design that makes apparent its operation. The rulers and margin setting in the word processor I use as I type this is one excellent example. The seat adjustment control shown in Figure 3.5 is another. Notice how the arrangement of the controls automatically refers to the operation each performs. Lift on the bottom seat control and the seat rises. Push forward on the vertical control and the seat back leans forward. That’s good conceptual design.

  FIGURE 3.4

  The designer’s model, the system image, and the user’s model.

  For someone to use a product successfully, they must have the same mental model (the user’s model) as that of the designer (the designer’s model). But the designer only talks to the user via the product itself, so the entire communication must take place through the “system image”: the information conveyed by the physical product itself.

  An important component of understanding comes from feedback: a device has to give continual feedback so that a user knows that it is working, that any commands, button presses, or other requests have actually been received. This feedback can be as simple as the feel of the brake pedal when you depress it and the resultant slowing of the automobile, or a brief flash of light or sound when you push something. It is amazing, though, how many products still give inadequate feedback. Most computer systems now display a clock face or an hourglass to indicate that they are responding, if slowly. If the delay is short, this indicator suffices, but it is completely inadequate if the delay lengthens. To be effective, feedback must enhance the conceptual model, indicating precisely what is happening and what yet remains to be done. Negative emotions kick in when there is a lack of understanding, when people feel frustrated and out of control—first uneasiness, then irritation, and, if the lack of control and understanding persists, even anger.

  FIGURE 3.5

  Seat controls—an excellent system image.

  These seat controls explain themselves: the conceptual model is provided by the positioning of the controls to look just like the item being controlled. Want to change the seat adjustment? Push or pull, lift or depress the corresponding control and the corresponding part of the seat moves accordingly. (Mercedes Benz seat controls; photograph by the author.)

  Usability is a complex topic. A product that does what is required, and is understandable, may still not be usable. Thus, guitars and violins do their assigned tasks well (that is, create music), they are quite simple to understand, but they are very difficult to use. The same is true of the piano, a deceptively simple-looking instrument. Musical instruments take years of dedicated practice to be used properly, and even then, errors and poor performance are common among nonprofessionals. The relative unusability of musical instruments is accepted, in part because we know of no other alternative, in part because the results are so worthwhile.

  But most of the things you use in everyday life should not require years of dedicated practice. New items appear every week, but who has the time or energy to spend the time required to learn each one? Bad design is a frequent cause of error, often unfairly blamed on users rather than on designers. Errors can lead to accidents that not only are financially expensive but can cause injury or death. There is no excuse for such flaws, for we understand how to build functional, understandable, and usable things. Moreover, everyday things have to be used by a wide variety of people: short and tall, athletic and not, who speak and read different languages, who may be deaf or blind, or lack physical mobility or agility—or even hands. Younger people have different skills and abilities than older ones.

  Usage is the critical test of a product: Here is where it stands alone, unsupported by advertising or merchandising material. All that matters is how well the product performs, how comfortable the person using it feels with the operation. A frustrated user is not a happy one, so it is at the behavioral stage of design that applying the principles of human-centered design pay off.

  Universal design, designing for everyone, is a challenge, but one well worth the effort. Indeed, the “Universal Design” philosophy argues persuasively that designing for the handicapped, the hard of hearing or seeing, or those less agile than average invariably makes an object better for everyone. There is no excuse not to design usable products that everyone can use.

  “HERE , TRY this.” I am visiting IDEO, the industrial design company. I am being shown their “Tech Box,” a big cabinet with an apparently endless set of small drawers and boxes, loaded with an eclectic combination of toys, textures, knobs, clever mechanical mechanisms, and objects that I cannot classify. I peer into the boxes, trying to figure out what they are for, what purpose they serve. “Just turn the knob,” I’m told, as something is thrust into my hands. I find the knob and rotate it. It feels good: smooth, silky. I try a different knob: it doesn’t feel as precise. There are dead regions where I turn and nothing seems to happen. Why the difference? Same mechanism, I am told: the difference is the addition of a special, very viscous oil. “Feel matters,” a designer explains, and from the “Tech Box” appear yet more examples: silky cloth, microfiber textiles, sticky rubber, squeezable balls—more than I can assimilate at one experience.

  Good designers worry a lot about the physical feel of their products. Physical touch and feel can make a huge difference in your appreciation of their creations. Consider the deligh
ts of smooth, polished metal, or soft leather, or a solid, mechanical knob that moves precisely from position to position, with no backlash or dead zones, no wobbling or wiggling. No wonder IDEO designers love their “Tech Box,” their collection of toys and textures, mechanisms and controls. Many design professionals focus on visual appearance, in part because this is what can be appreciated from a distance and, of course, all that can be experienced in an advertising or marketing photograph or printed illustration. Touch and feel, however, are critical to our behavioral assessment of a product. Recall the shower of figure 3.3.

  Physical objects have weight, texture, and surface. The design term for this is “tangibility.” Far too many high-technology creations have moved from real physical controls and products to ones that reside on computer screens, to be operated by touching the screen or manipulating a mouse. All the pleasure of manipulating a physical object is gone and, with it, a sense of control. Physical feel matters. We are, after all, biological creatures, with physical bodies, arms, and legs. A huge amount of the brain is taken up by the sensory systems, continually probing and interacting with the environment. The best of products make full use of this interaction. Just imagine cooking, feeling the comfort of a balanced, high-quality knife, hearing the sound of cutting on the chopping board or the sizzle when you drop food into the skillet, smelling the odors released from the fresh-cut food. Or imagine gardening, feeling the tenderness of a plant, the grittiness of the earth. Or playing tennis, hearing the twang of the ball against the racket’s strings, its feel in your hands. Touch, vibration, feel, smell, sound, visual appearance. And now imagine doing all this on a computer screen, where what you see may look real, but with no feel, no scent, no vibrations, no sound.

  The world of software is to be commended for its power and chameleon-like ability to transform itself into whatever function is needed. The computer provides for abstract actions. Computer scientists call these environments “virtual worlds,” and although they have many benefits, they eliminate one of the great delights of real interactions: the delight that comes from touching, feeling, and moving real physical objects.

  The virtual worlds of software are worlds of cognition: ideas and concepts presented without physical substance. Physical objects involve the world of emotion, where you experience things, whether the comfortable sensuousness of some surfaces or the grating, uncomfortable feel of others. Although software and computers have become indispensable to daily life, too much adherence to the abstraction of the computer screen subtracts from emotional pleasure. Fortunately, some designers of many computer-based products are restoring the natural, affective pleasures of the real, tangible world. Physical controls are back in style: knobs for tuning, knobs for volume, levers for turning or switching. Hurrah!

  Badly conceived behavioral design can lead to great frustration, leading to objects that have lives of their own, that refuse to obey, that provide inadequate feedback about their actions, that are unintelligible, and all in all, putting anyone who tries to use them into a big, gray funk. No wonder this frustration often erupts in rage, causes the user to kick, scream, and curse. Worse, there is no excuse for such frustration. The fault does not lie with the user; the fault lies with the design.

  Why do so many designs fail? Mainly because designers and engineers are often self-centered. Engineers tend to focus upon technology, putting into a product whatever special features they themselves prefer. Many designers fail as well through their fondness for the sophisticated use of images, metaphors, and semantics that win prizes in design competitions but create products that are inaccessible to users. Web sites fail here as well, for the creators focus either upon the technical sophistication of images and sounds, or upon making sure that each division of a company receives the recognition that its political power dictates.

  None of these cases takes into account the concerns of the poor user, people like you and me, who use a product or web site to satisfy some need. You need to accomplish a task or to find some information. You don’t know the organizational chart of the company on whose web site you seek information, nor do you wish to. You may enjoy flashy images and sounds briefly, but not when that cleverness and sophistication get in the way of getting your job done.

  Good behavioral design should be human-centered, focusing upon understanding and satisfying the needs of the people who actually use the product. As I have said, the best way to discover these needs is through observation, when the product is being used naturally, and not in response to some arbitrary request to “show us how you would do x.” But observation is surprisingly rare. You would think that manufacturers would want to watch people use their products, the better to improve them for the future. But no, they are too busy designing and matching the features of the competition to find out whether their products are really effective and usable.

  Engineers and designers explain that, being people themselves, they understand people, but this argument is flawed. Engineers and designers simultaneously know too much and too little. They know too much about the technology and too little about how other people live their lives and do their activities. In addition, anyone involved with a product is so close to the technical details, to the design difficulties, and to the project issues that they are unable to view the product the way an unattached person can.

  Focus groups, questionnaires, and surveys are poor tools for learning about behavior, for they are divorced from actual use. Most behavior is subconscious and what people actually do can be quite different from what they think they do. We humans like to think that we know why we act as we do, but we don’t, however much we like to explain our actions. The fact that both visceral and behavioral reactions are subconscious makes us unaware of our true reactions and their causes. This is why trained professionals who observe real use in real situations can often tell more about people’s likes and dislikes—and the reasons for them—than the people themselves.

  An interesting exception to these problems comes when designers or engineers are building something for themselves that they will use frequently in their own everyday lives. Such products tend to excel. As a result, the best products today, from a behavioral point of view, are often those that come from the athletic, sports, and craft industries, because these products do get designed, purchased, and used by people who put behavior above everything else. Go to a good hardware store and examine the hand tools used by gardeners, woodworkers, and machinists. These tools, developed over centuries of use, are carefully designed to feel good, to be balanced, to give precise feedback, and to perform well. Go to a good outfitter’s shop and look at a mountain climber’s tools or at the tents and backpacks used by serious hikers and campers. Or go to a professional chef’s supply house and examine what real chefs buy and use in their kitchens.

  I have found it interesting to compare the electronic equipment sold for consumers with the equipment sold to professionals. Although much more expensive, the professional equipment tends to be simpler and easier to use. Video recorders for the home market have numerous flashing lights, many buttons and settings, and complex menus for setting the time and programming future recording. The recorders for the professionals just have the essentials and are therefore easier to use while functioning better. This difference arises, in part, because the designers will be using the products themselves, so they know just what is important and what is not. Tools made by artisans for themselves all have this property. Designers of hiking or mountain climbing equipment may one day find their lives depending upon the quality and behavior of their own designs.

  When the company Hewlett Packard was founded, their main product was test equipment for electrical engineers. “Design for the person on the next bench,” was the company motto, and it served them well. Engineers found that HP products were a joy to use because they fitted the task of the electrical engineer at the design or test bench perfectly. But today, the same design philosophy no longer works: the equipment is often used by technicians and field
crew who have little or no technical background. The “next bench” philosophy that worked when the designers were also users fails when the populations change.

  Good behavioral design has to be a fundamental part of the design process from the very start; it cannot be adopted once the product has been completed. Behavioral design begins with understanding the user’s needs, ideally derived by conducting studies of relevant behavior in homes, schools, places of work, or wherever the product will actually be used. Then the design team produces quick, rapid prototypes to test on prospective users, prototypes that take hours (not days) to build and then to test. Even simple sketches or mockups from cardboard, wood, or foam work well at this stage. As the design process continues, it incorporates the information from the tests. Soon the prototypes are more complete, sometimes fully or partially working, sometimes simply simulating working devices. By the time the product is finished, it has been thoroughly vetted through usage: final testing is necessary only to catch minor mistakes in implementation. This iterative design process is the heart of effective, user-centered design.

  Reflective Design

  Reflective design covers a lot of territory. It is all about message, about culture, and about the meaning of a product or its use. For one, it is about the meaning of things, the personal remembrances something evokes. For another, very different thing, it is about self-image and the message a product sends to others. Whenever you notice that the color of someone’s socks matches the rest of his or her clothes or whether those clothes are right for the occasion, you are concerned with reflective self-image.