“Good design is actually a lot harder to notice than poor design, in part because good designs fit our needs so well that the design is invisible, serving us without drawing attention to itself. Bad design, on the other hand, screams out its inadequacies, making itself very noticeable.”
The above quote is from the preface to the new edition of The Design of Everyday Things, which will be published in November (the preface is already available). If I’d known a new edition was coming so soon, I might’ve waited a few months, but as it is, the 1988 edition holds up fairly well. The examples are outdated, but the principles remain sound, and Norman even predicted certain technological advances (the smartphone, for example).
Norman’s principles of design truly do apply to everything that people make and use, from the simple (doors) to the advanced (computers). Though technology has improved since 1988 (now, of course, computers are everyday things), some of the same design flaws persist, and Norman’s decades-old observation still holds true to some extent: “[D]esigners of computer systems seem particularly oblivious to the needs of users…” Designers, who know their products well, often fall into the trap of thinking that they are the typical user, when in fact, they usually cannot predict the type of errors that users will commit.
So, what are these principles?
Visibility: Is it clear from examining the object in question how it can be used, or what should be done with it? For example, is the on/off switch in the front, or hidden around the back? I thought of an example of poor visibility right away: at our library, we have a coin box where patrons pay for their print jobs. This box is designed so that coins go in a slot at the top. The machine also accepts $1 and $5 bills, but the slot for the dollar bills is placed on the front of the box but very far down, near the floor. Patrons frequently come to the desk to get change for a bill, and we show them that the machine does in fact accept bills. A lot of them apologize for bothering us and blame themselves for not seeing the bill slot, but really, it is a bad design: the bill and coin slots should be grouped together.
Natural mapping: Essentially, does the way a thing works make sense? A joystick or a mouse employs natural mapping: forward=up, backward=down, left=left, right=right. Likewise a steering wheel in a car: turn right to move right, and left to move left. The opposite would be counterintuitive, confusing, and frustrating, and would lead to frequent error.
Conceptual model: Norman writes about three aspects of mental models: the design model, the system image, and the user’s model. The design model is the designer’s mental map of how their product works; the system image is what the product shows to the user; and the user’s model is a mental map of how they think the product works. In the preface to the 2002 edition, Norman writes, “Design is really an act of communication, which means having a deep understanding of the person with whom the designer is communicating.” Because the designer and the user don’t communicate directly, the user’s only insight into the designer’s mind is through the system image. Therefore, the designer must “explain” through the system image how the product works, and guide the user to perform the correct actions for the task they want to complete – not an easy feat. However, Norman writes, as a rule of thumb, “When instructions have to be pasted on something…it is badly designed.” Things work best when the designer and the user have similar conceptual models.
Feedback: Once the user has completed an action, how does s/he know whether it has worked or not? Humans generally are not comfortable with uncertainty, so a good design provides feedback to explain what is happening or has happened. “Design should…make sure that (1) the user can figure out what to do, and (2) the user can tell what is going on.” Feedback includes everything from progress bars (“Your download is 58% complete”) to descriptive error messages with helpful next steps.
While reading The Design of Everyday Things, Clarke’s Third Law came to mind: “Any sufficiently advanced technology is indistinguishable from magic” (Arthur C. Clarke). When processes become invisible, they come to seem magical and mysterious. The flip side is that “magic” is hard to take apart, fix, and put back together; cellphones aren’t like old radios. With much of today’s technology, it is difficult for users to tell what is happening, and, if something is going wrong, how to fix it. The Design of Everyday Things doesn’t necessarily help users who are frustrated with a product (except by assuring them that it likely isn’t their fault, but rather the fault of the design), but it does help us recognize bad design, think about how it could be better, and appreciate good design.
More quotes from the book can be found in my Goodreads review.