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The DESIGN
of EVERYDAY
THINGS
DON
NORMAN
R E V I S E D & E X PA N D E D E D I T I O N
Cover design by Nicole Caputo
Cover image: Jacques Carelman “Co� ee Pot for Masochists” 
© 2013 Artists Rights Society (ARS), New York / ADAGP, Paris
BUSINESS / PSYCHOLOGY
A Member of the Perseus Books Group
www.basickbooks.com
ISBN 978-0-465-05065-9
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5 1 7 9 9
$17.99 US / $21.00 CAN
Even the smartest among us can feel inept as we try to fi gure out the shower control in a hotel or attempt to navigate an unfamiliar television set or stove. When The Design of Everyday Things was published in 1988, cognitive scientist Don Norman provocatively proposed that the fault 
lies not in ourselves but in design that ignores the needs and psychology of people. Alas, bad design 
is everywhere, but fortunately, it isn’t di� cult to design things that are understandable, usable, and 
enjoyable. Thoughtfully revised to keep the timeless principles of psychology up to date with ever-
changing new technologies, The Design of Everyday Things is a powerful appeal for good design, and 
a reminder of how—and why—some products satisfy while others only disappoint.
“Part operating manual for designers and part manifesto on the power of designing for people, 
The Design of Everyday Things is even more relevant today than it was when fi rst published.” 
—TIM BROWN, CEO, IDEO, and author of Change by Design
DON NORMAN is a co-founder of the Nielsen Norman Group, and holds graduate degrees 
in both engineering and psychology. His many books include Emotional Design, The Design of Future 
Things, and Living with Complexity. He lives in Silicon Valley, California.
WWW.JND.ORG
“Design may be our top competitive edge. This book is a joy—fun and of the utmost importance.”
—TOM PETERS, author of In Search of Excellence
“This book changed the fi eld of design. As the pace of technological change accelerates, the 
principles in this book are increasingly important. The new examples and ideas 
 about design and product development make it essential reading.” 
 —PATR ICK W H ITNEY, Dean, Institute of Design, and Steelcase/Robert C. Pew 
Professor of Design, Illinois Institute of Technology
“Norman enlightened me when I was a student of psychology decades ago and he 
continues to inspire me as a professor of design. The cumulated insights and wisdom of the cross- 
disciplinary genius Donald Norman are a must for designers and a joy for 
those who are interested in artifacts and people.” 
—CEES DE BONT, Dean, School of Design, and Chair Professor of 
Industrial Design, The Hong Kong Polytechnic University
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ALSO BY 
DON NORMAN
TEXTBOOKS
Memory and Attention: An Introduction to 
Human Information Processing. 
First edition, 1969; second edition 1976
Human Information Processing. 
(with Peter Lindsay: first edition, 1972; second edition 1977)
SCIE NTIFIC MONOGR A PHS
Models of Human Memory 
(edited, 1970)
Explorations in Cognition 
(with David E. Rumelhart and the LNR Research Group, 1975)
Perspectives on Cognitive Science
(edited, 1981)
User Centered System Design: New Perspectives on 
Human-Computer Interaction 
(edited with Steve Draper, 1986)
TR A DE BOOKS
Learning and Memory, 1982
The Psychology of Everyday Things, 1988
The Design of Everyday Things
1990 and 2002 (paperbacks of The Psychology of Everyday Things 
with new prefaces)
The Design of Everyday Things
Revised and Expanded Edition, 2013
Turn Signals Are the Facial Expressions of Automobiles, 1992
Things That Make Us Smart, 1993
The Invisible Computer: Why Good Products Can Fail, the Personal 
Computer Is So Complex, and Information Appliances Are the 
Answer, 1998
Emotional Design: Why We Love (or Hate) Everyday Things, 2004
The Design of Future Things, 2007
A Comprehensive Strategy for Better Reading: Cognition and 
Emotion, 2010
(with Masanori Okimoto; my essays, with commentary in Japanese, used 
for teaching English as a second language to Japanese speakers)
Living with Complexity, 2011
CD-ROM
First person: Donald A. Norman. Defending Human Attributes 
in the Age of the Machine, 1994
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THE
DESIGN
OF EVERYDAY
THINGS
R E V I S E D A N D E X PA N DE D E DI T I O N
Don Norman
A Member of the Perseus Books Group
New York
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Copyright © 201 3 by Don Norman
Published by Basic Books,
A Member of the Perseus Books Group
All rights reserved. Printed in the United States of America. No part 
of this book may be reproduced in any manner whatsoever without 
written permission except in the case of brief quotations embodied in 
critical articles and reviews. For information, address Basic Books, 
250 West 57th Street, 15th Floor, New York, New York 10107.
Books published by Basic Books are available at special discounts for 
bulk purchases in the United States by corporations, institutions, and 
other organizations. For more information, please contact the Special 
Markets Department at the Perseus Books Group, 2300 Chestnut 
Street, Suite 200, Philadelphia, PA 19103, or call (800) 810-4145, 
ext. 5000, or e-mail special.markets@perseusbooks.com.
Library of Congress Cataloging-in-Publication Data
Norman, Donald A.
[Psychology of everyday things]
 The design of everyday things / Don Norman.—Revised 
 and expanded edition.
 pages cm
 ISBN 978-0-465-05065-9 (pbk.)—ISBN 978-0-465-00394-5 
 (ebook) 1. Industrial design—Psychological aspects. 2. Human 
 engineering. I. Title.
 TS171.4.N67 2013
 745.2001'9—dc23
2013024417
10 9 8 7 6 5 4 3 2 1
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For Julie
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 vii
CONTENTS
 Preface to the Revised Edition xi
 1 The Psychopathology of Everyday Things 1
 The Complexity of Modern Devices, 4
 Human-Centered Design, 8
 Fundamental Principles of Interaction, 10
 The System Image, 31
 The Paradox of Technology, 32
 The Design Challenge, 34
 2 The Psychology of Everyday Actions 37
 How People Do Things: The Gulfs of Execution
 and Evaluation, 38
 The Seven Stages of Action, 40
 Human Thought: Mostly Subconscious, 44
 Human Cognition and Emotion, 49
 The Seven Stages of Action and the 
 Three Levels of Processing, 55
 People as Storytellers, 56
 Blaming the Wrong Things, 59
 Falsely Blaming Yourself, 65
 The Seven Stages of Action: 
 Seven Fundamental Design Principles, 71
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viii Contents
 3 Knowledge in the Head and in the World 74
 Precise Behavior from Imprecise Knowledge, 75
 Memory Is Knowledge in the Head, 86
 The Structure of Memory, 91
 Approximate Models: Memory in the 
 Real World, 100
 Knowledge in the Head, 105
 The Tradeoff Between Knowledge in the World 
 and in the Head, 109
 Memory in Multiple Heads, Multiple Devices, 111
 Natural Mapping, 113
 Culture and Design: Natural Mappings Can 
 Vary with Culture, 118
 4 Knowing What to Do: Constraints, 123 
Discoverability, and Feedback
 Four Kinds of Constraints: Physical, Cultural, 
 Semantic, and Logical, 125
 Applying Affordances, Signifiers, and 
 Constraints to Everyday Objects, 132
 Constraints That Force the Desired Behavior, 141
 Conventions,Constraints, and Affordances, 145
 The Faucet: A Case History of Design, 150
 Using Sound as Signifiers, 155
 5 Human Error? No, Bad Design 162
 Understanding Why There Is Error, 163
 Deliberate Violations, 169
 Two Types of Errors: Slips and Mistakes, 170
 The Classification of Slips, 173
 The Classification of Mistakes, 179
 Social and Institutional Pressures, 186
 Reporting Error, 191
 Detecting Error, 194
 Designing for Error, 198
 When Good Design Isn’t Enough, 210
 Resilience Engineering, 211
 The Paradox of Automation, 213
 Design Principles for Dealing with Error, 215
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 Contents ix
 6 Design Thinking 217
 Solving the Correct Problem, 218
 The Double-Diamond Model of Design, 220
 The Human-Centered Design Process, 221
 What I Just Told You? It Doesn’t Really Work 
 That Way, 236
 The Design Challenge, 239
 Complexity Is Good; It Is Confusion 
 That Is Bad, 247
 Standardization and Technology, 248
 Deliberately Making Things Difficult, 255
 Design: Developing Technology for People, 257
 7 Design in the World of Business 258
 Competitive Forces, 259
 New Technologies Force Change, 264
 How Long Does It Take to Introduce a 
 New Product?, 268
 Two Forms of Innovation: Incremental 
 and Radical, 279
 The Design of Everyday Things: 1988–2038, 282
 The Future of Books, 288
 The Moral Obligations of Design, 291
 Design Thinking and Thinking About Design, 293
 Acknowledgments 299
 General Readings and Notes 305
 References 321
 Index 331
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 xi
PREFACE TO 
THE REVISED EDITION
In the first edition of this book, then called POET, The Psychology 
of Everyday Things, I started with these lines: “This is the book I 
always wanted to write, except I didn’t know it.” Today I do know 
it, so I simply say, “This is the book I always wanted to write.”
This is a starter kit for good design. It is intended to be enjoy-
able and informative for everyone: everyday people, technical peo-
ple, designers, and nondesigners. One goal is to turn readers into 
great observers of the absurd, of the poor design that gives rise 
to so many of the problems of modern life, especially of modern 
technology. It will also turn them into observers of the good, of 
the ways in which thoughtful designers have worked to make our 
lives easier and smoother. 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.
Along the way I lay out the fundamental principles required 
to eliminate problems, to turn our everyday stuff into enjoyable 
products that provide pleasure and satisfaction. The combination 
of good observation skills and good design principles is a powerful 
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xii Preface to the Revised Edition
tool, one that everyone can use, even people who are not profes-
sional designers. Why? Because we are all designers in the sense 
that all of us deliberately design our lives, our rooms, and the way 
we do things. We can also design workarounds, ways of overcom-
ing the flaws of existing devices. So, one purpose of this book is to 
give back your control over the products in your life: to know how 
to select usable and understandable ones, to know how to fix those 
that aren’t so usable or understandable.
The first edition of the book has lived a long and healthy life. Its 
name was quickly changed to Design of Everyday Things (DOET) 
to make the title less cute and more descriptive. DOET has been 
read by the general public and by designers. It has been assigned 
in courses and handed out as required readings in many compa-
nies. Now, more than twenty years after its release, the book is 
still popular. I am delighted by the response and by the number 
of people who correspond with me about it, who send me further 
examples of thoughtless, inane design, plus occasional examples 
of superb design. Many readers have told me that it has changed 
their lives, making them more sensitive to the problems of life and 
to the needs of people. Some changed their careers and became 
designers because of the book. The response has been amazing.
Why a Revised Edition?
In the twenty-five years that have passed since the first edition 
of the book, technology has undergone massive change. Neither 
cell phones nor the Internet were in widespread usage when I 
wrote the book. Home networks were unheard of. Moore’s law 
proclaims that the power of computer processors doubles roughly 
every two years. This means that today’s computers are five thou-
sand times more powerful than the ones available when the book 
was first written.
Although the fundamental design principles of The Design of 
Everyday Things are still as true and as important as when the first 
edition was written, the examples were badly out of date. “What 
is a slide projector?” students ask. Even if nothing else was to be 
changed, the examples had to be updated.
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 Preface to the Revised Edition xiii
The principles of effective design also had to be brought up to 
date. Human-centered design (HCD) has emerged since the first 
edition, partially inspired by that book. This current edition has 
an entire chapter devoted to the HCD process of product devel-
opment. The first edition of the book focused upon making prod-
ucts understandable and usable. The total experience of a product 
covers much more than its usability: aesthetics, pleasure, and fun 
play critically important roles. There was no discussion of plea-
sure, enjoyment, or emotion. Emotion is so important that I wrote 
an entire book, Emotional Design, about the role it plays in design. 
These issues are also now included in this edition.
My experiences in industry have taught me about the com-
plexities of the real world, how cost and schedules are critical, 
the need to pay attention to competition, and the importance of 
multi disciplinary teams. I learned that the successful product has 
to appeal to customers, and the criteria they use to determine what 
to purchase may have surprisingly little overlap with the aspects 
that are important during usage. The best products do not always 
succeed. Brilliant new technologies might take decades to become 
accepted. To understand products, it is not enough to understand 
design or technology: it is critical to understand business.
What Has Changed?
For readers familiar with the earlier edition of this book, here is a 
brief review of the changes.
What has changed? Not much. Everything.
When I started, I assumed that the basic principles were still 
true, so all I needed to do was update the examples. But in the 
end, I rewrote everything. Why? Because although all the princi-
ples still applied, in the twenty-five years since the first edition, 
much has been learned. I also now know which parts were diffi-
cult and therefore need better explanations. In the interim, I also 
wrote many articles and six books on related topics, some of which 
I thought important to include in the revision. For example, the 
original book says nothing of what has come to be called user 
experience (a term that I was among the first to use, when in the 
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xiv Preface to the Revised Edition
early 1990s, the group I headed at Apple calleditself “the User 
Experience Architect’s Office”). This needed to be here.
Finally, my exposure to industry taught me much about the way 
products actually get deployed, so I added considerable infor-
mation about the impact of budgets, schedules, and competitive 
pressures. When I wrote the original book, I was an academic re-
searcher. Today, I have been an industry executive (Apple, HP, and 
some startups), a consultant to numerous companies, and a board 
member of companies. I had to include my learnings from these 
experiences.
Finally, one important component of the original edition was 
its brevity. The book could be read quickly as a basic, general 
introduction. I kept that feature unchanged. I tried to delete as 
much as I added to keep the total size about the same (I failed). 
The book is meant to be an introduction: advanced discussions of 
the topics, as well as a large number of important but more ad-
vanced topics, have been left out to maintain the compactness. The 
previous edition lasted from 1988 to 2013. If the new edition is to 
last as long, 2013 to 2038, I had to be careful to choose examples 
that would not be dated twenty-five years from now. As a result, 
I have tried not to give specific company examples. After all, who 
remembers the companies of twenty-five years ago? Who can 
predict what new companies will arise, what existing companies 
will disappear, and what new technologies will arise in the next 
twenty-five years? The one thing I can predict with certainty is that 
the principles of human psychology will remain the same, which 
means that the design principles here, based on psychology, on the 
nature of human cognition, emotion, action, and interaction with 
the world, will remain unchanged.
Here is a brief summary of the changes, chapter by chapter.
Chapter 1: The Psychopathology of Everyday Things
Signifiers are the most important addition to the chapter, a con-
cept first introduced in my book Living with Complexity. The first 
edition had a focus upon affordances, but although affordances 
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 Preface to the Revised Edition xv
make sense for interaction with physical objects, they are con-
fusing when dealing with virtual ones. As a result, affordances 
have created much confusion in the world of design. Affor-
dances define what actions are possible. Signifiers specify how 
people discover those possibilities: signifiers are signs, percep-
tible signals of what can be done. Signifiers are of far more im-
portance to designers than are affordances. Hence, the extended 
treatment.
I added a very brief section on HCD, a term that didn’t yet exist 
when the first edition was published, although looking back, we 
see that the entire book was about HCD.
Other than that, the chapter is the same, and although all the 
photographs and drawings are new, the examples are pretty much 
the same.
Chapter 2: The Psychology of Everyday Actions
The chapter has one major addition to the coverage in the first edi-
tion: the addition of emotion. The seven-stage model of action has 
proven to be influential, as has the three-level model of processing 
(introduced in my book Emotional Design). In this chapter I show 
the interplay between these two, show that different emotions 
arise at the different stages, and show which stages are primarily 
located at each of the three levels of processing (visceral, for the 
elementary levels of motor action performance and perception; be-
havioral, for the levels of action specification and initial interpre-
tation of the outcome; and reflective, for the development of goals, 
plans, and the final stage of evaluation of the outcome).
Chapter 3: Knowledge in the Head and in the World
Aside from improved and updated examples, the most important 
addition to this chapter is a section on culture, which is of special 
importance to my discussion of “natural mappings.” What seems 
natural in one culture may not be in another. The section examines 
the way different cultures view time—the discussion might sur-
prise you.
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xvi Preface to the Revised Edition
Chapter. 4: Knowing What to Do: 
Constraints, Discoverability, and Feedback
Few substantive changes. Better examples. The elaboration of forc-
ing functions into two kinds: lock-in and lockout. And a section 
on destination control elevators, illustrating how change can be 
extremely disconcerting, even to professionals, even if the change 
is for the better.
Chapter 5: Human Error? No, Bad Design
The basics are unchanged, but the chapter itself has been heavily 
revised. I update the classification of errors to fit advances since 
the publication of the first edition. In particular, I now divide slips 
into two main categories—action-based and memory lapses; and 
mistakes into three categories—rule-based, knowledge-based, 
and memory lapses. (These distinctions are now common, but I 
introduce a slightly different way to treat memory lapses.)
Although the multiple classifications of slips provided in the 
first edition are still valid, many have little or no implications for 
design, so they have been eliminated from the revision. I provide 
more design-relevant examples. I show the relationship of the clas-
sification of errors, slips, and mistakes to the seven-stage model of 
action, something new in this revision.
The chapter concludes with a quick discussion of the difficulties 
posed by automation (from my book The Design of Future Things) 
and what I consider the best new approach to deal with design 
so as to either eliminate or minimize human error: resilience 
engineering.
Chapter 6: Design Thinking
This chapter is completely new. I discuss two views of human-
centered design: the British Design Council’s double-diamond 
model and the traditional HCD iteration of observation, ide-
ation, prototyping, and testing. The first diamond is the diver-
gence, followed by convergence, of possibilities to determine 
the appropriate problem. The second diamond is a divergence-
convergence to determine an appropriate solution. I introduce 
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 Preface to the Revised Edition xvii
activity-centered design as a more appropriate variant of human-
centered design in many circumstances. These sections cover 
the theory.
The chapter then takes a radical shift in position, starting with a 
section entitled “What I Just Told You? It Doesn’t Really Work That 
Way.” Here is where I introduce Norman’s Law: The day the prod-
uct team is announced, it is behind schedule and over its budget.
I discuss challenges of design within a company, where sched-
ules, budgets, and the competing requirements of the different 
divisions all provide severe constraints upon what can be accom-
plished. Readers from industry have told me that they welcome 
these sections, which capture the real pressures upon them.
The chapter concludes with a discussion of the role of standards 
(modified from a similar discussion in the earlier edition), plus 
some more general design guidelines.
Chapter 7: Design in the World of Business
This chapter is also completely new, continuing the theme started 
in Chapter 6 of design in the real world. Here I discuss “featuritis,” 
the changes being forced upon us through the invention of new 
technologies, and the distinction between incremental and radical 
innovation. Everyone wants radical innovation, but the truth is, 
most radical innovations fail, and even when they do succeed, it 
can take multiple decades before they are accepted. Radical innova-
tion, therefore, is relatively rare: incremental innovation is common.
The techniques of human-centered design are appropriate to in-
crementalinnovation: they cannot lead to radical innovations.
The chapter concludes with discussions of the trends to come, 
the future of books, the moral obligations of design, and the rise of 
small, do-it-yourself makers that are starting to revolutionize the 
way ideas are conceived and introduced into the marketplace: 
“the rise of the small,” I call it.
Summary
With the passage of time, the psychology of people stays the same, 
but the tools and objects in the world change. Cultures change. 
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xviii Preface to the Revised Edition
Technologies change. The principles of design still hold, but the 
way they get applied needs to be modified to account for new ac-
tivities, new technologies, new methods of communication and 
interaction. The Psychology of Everyday Things was appropriate for 
the twentieth century: The Design of Everyday Things is for the 
twenty-first.
Don Norman
Silicon Valley, California
www.jnd.org
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 1
THE PSYCHOPATHOLOGY 
OF EVERYDAY 
THINGS
If I were placed in the cockpit of a modern jet airliner, 
my inability to perform well would neither surprise nor 
bother me. But why should I have trouble with doors 
and light switches, water faucets and stoves? “Doors?” I 
can hear the reader saying. “You have trouble opening doors?” Yes. 
I push doors that are meant to be pulled, pull doors that should be 
pushed, and walk into doors that neither pull nor push, but slide. 
Moreover, I see others having the same troubles—unnecessary 
troubles. My problems with doors have become so well known 
that confusing doors are often called “Norman doors.” Imagine 
becoming famous for doors that don’t work right. I’m pretty sure 
that’s not what my parents planned for me. (Put “Norman doors” 
into your favorite search engine—be sure to include the quote 
marks: it makes for fascinating reading.)
How can such a simple thing as a door be so confusing? A door 
would seem to be about as simple a device as possible. There is not 
much you can do to a door: you can open it or shut it. Suppose you 
are in an office building, walking down a corridor. You come to a 
door. How does it open? Should you push or pull, on the left or the 
right? Maybe the door slides. If so, in which direction? I have seen 
doors that slide to the left, to the right, and even up into the ceiling. 
C H A P T E R O N E
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2 The Design of Everyday Things
The design of the door should indicate how to work it without any 
need for signs, certainly without any need for trial and error.
A friend told me of the time he got trapped in the doorway of a 
post office in a European city. The entrance was an imposing row 
of six glass swinging doors, followed immediately by a second, 
identical row. That’s a standard design: it helps reduce the airflow 
and thus maintain the indoor temperature of the building. There 
was no visible hardware: obviously the doors could swing in ei-
ther direction: all a person had to do was push the side of the door 
and enter.
My friend pushed on one of the outer doors. It swung inward, 
and he entered the building. Then, before he could get to the next 
row of doors, he was distracted and turned around for an instant. 
He didn’t realize it at the time, but he had moved slightly to the 
right. So when he came to the next door and pushed it, nothing 
happened. “Hmm,” he thought, “must be locked.” So he pushed 
the side of the adjacent door. Nothing. Puzzled, my friend decided 
to go outside again. He turned around and pushed against the 
side of a door. Nothing. He pushed the adjacent door. Nothing. 
The door he had just entered no longer worked. He turned around 
once more and tried the inside doors again. Nothing. Concern, 
then mild panic. He was trapped! Just then, a group of people on 
the other side of the entranceway (to my friend’s right) passed eas-
ily through both sets of doors. My friend hurried over to follow 
their path.
FIGURE 1.1 . Coffeepot for Masochists. The 
French artist Jacques Carelman in his series of 
books Catalogue d’objets introuvables (Catalog of 
unfindable objects) provides delightful examples 
of everyday things that are deliberately unwork-
able, outrageous, or otherwise ill-formed. One 
of my favorite items is what he calls “coffeepot for 
masochists.” The photograph shows a copy given 
to me by collegues at the University of California, 
San Diego. It is one of my treasured art objects. 
(Photograph by Aymin Shamma for the author.)
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 one: The Psychopathology of Everyday Things 3
How could such a thing happen? A swinging door has two sides. 
One contains the supporting pillar and the hinge, the other is un-
supported. To open the door, you must push or pull on the unsup-
ported edge. If you push on the hinge side, nothing happens. In 
my friend’s case, he was in a building where the designer aimed 
for beauty, not utility. No distracting lines, no visible pillars, no vis-
ible hinges. So how can the ordinary user know which side to push 
on? While distracted, my friend had moved toward the (invisible) 
supporting pillar, so he was pushing the doors on the hinged side. 
No wonder nothing happened. Attractive doors. Stylish. Probably 
won a design prize.
Two of the most important characteristics of good design are dis-
coverability and understanding. Discoverability: Is it possible to even 
figure out what actions are possible and where and how to per-
form them? Understanding: What does it all mean? How is the 
product supposed to be used? What do all the different controls 
and settings mean?
The doors in the story illustrate what happens when discoverabil-
ity fails. Whether the device is a door or a stove, a mobile phone 
or a nuclear power plant, the relevant components must be visible, 
and they must communicate the correct message: What actions 
are possible? Where and how should they be done? With doors 
that push, the designer must provide signals that naturally indi-
cate where to push. These need not destroy the aesthetics. Put a 
vertical plate on the side to be pushed. Or make the supporting 
pillars visible. The vertical plate and supporting pillars are natural 
signals, naturally interpreted, making it easy to know just what to 
do: no labels needed.
With complex devices, discoverability and understanding re-
quire the aid of manuals or personal instruction. We accept this 
if the device is indeed complex, but it should be unnecessary for 
simple things. Many products defy understanding simply because 
they have too many functions and controls. I don’t think that sim-
ple home appliances—stoves, washing machines, audio and tele-
vision sets—should look like Hollywood’s idea of a spaceship 
control room. They already do, much to our consternation. Faced 
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4 The Design of Everyday Things
with a bewildering array of controls and displays, we simply mem-
orize one or two fixed settings to approximate what is desired.
In England I visited a home with a fancy new Italian washer-
dryer combination, with super-duper multisymbol controls, all to 
do everything anyone could imagine doing with the washing and 
drying of clothes. The husband (an engineering psychologist) said 
he refused to go near it. The wife (a physician) said she had simply 
memorized one setting and tried to ignore the rest. I asked to see 
the manual: it was just as confusing as the device. The whole pur-
pose of the design is lost.
The Complexity of Modern Devices
All artificial things are designed. Whether it is the layout of fur-niture in a room, the paths through a garden or forest, or the in-
tricacies of an electronic device, some person or group of people 
had to decide upon the layout, operation, and mechanisms. Not 
all designed things involve physical structures. Services, lectures, 
rules and procedures, and the organizational structures of busi-
nesses and governments do not have physical mechanisms, but 
their rules of operation have to be designed, sometimes informally, 
sometimes precisely recorded and specified.
But even though people have designed things since prehistoric 
times, the field of design is relatively new, divided into many areas 
of specialty. Because everything is designed, the number of areas is 
enormous, ranging from clothes and furniture to complex control 
rooms and bridges. This book covers everyday things, focusing on 
the interplay between technology and people to ensure that the 
products actually fulfill human needs while being understand-
able and usable. In the best of cases, the products should also be 
delightful and enjoyable, which means that not only must the re-
quirements of engineering, manufacturing, and ergonomics be sat-
isfied, but attention must be paid to the entire experience, which 
means the aesthetics of form and the quality of interaction. The 
major areas of design relevant to this book are industrial design, 
interaction design, and experience design. None of the fields is 
well defined, but the focus of the efforts does vary, with industrial 
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 one: The Psychopathology of Everyday Things 5
designers emphasizing form and material, interactive designers 
emphasizing understandability and usability, and experience de-
signers emphasizing the emotional impact. Thus:
Industrial design: The professional service of creating and developing 
concepts and specifications that optimize the function, value, and 
appearance of products and systems for the mutual benefit of both 
user and manufacturer (from the Industrial Design Society of America’s 
website).
Interaction design: The focus is upon how people interact with tech-
nology. The goal is to enhance people’s understanding of what can be 
done, what is happening, and what has just occurred. Interaction de-
sign draws upon principles of psychology, design, art, and emotion 
to ensure a positive, enjoyable experience.
Experience design: The practice of designing products, processes, ser-
vices, events, and environments with a focus placed on the quality 
and enjoyment of the total experience.
Design is concerned with how things work, how they are con-
trolled, and the nature of the interaction between people and 
technology. When done well, the results are brilliant, pleasurable 
products. When done badly, the products are unusable, leading to 
great frustration and irritation. Or they might be usable, but force 
us to behave the way the product wishes rather than as we wish.
Machines, after all, are conceived, designed, and constructed by 
people. By human standards, machines are pretty limited. They 
do not maintain the same kind of rich history of experiences that 
people have in common with one another, experiences that enable 
us to interact with others because of this shared understanding. 
Instead, machines usually follow rather simple, rigid rules of be-
havior. If we get the rules wrong even slightly, the machine does 
what it is told, no matter how insensible and illogical. People are 
imaginative and creative, filled with common sense; that is, a lot of 
valuable knowledge built up over years of experience. But instead 
of capitalizing on these strengths, machines require us to be precise 
and accurate, things we are not very good at. Machines have no 
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6 The Design of Everyday Things
leeway or common sense. Moreover, many of the rules followed 
by a machine are known only by the machine and its designers.
When people fail to follow these bizarre, secret rules, and the 
machine does the wrong thing, its operators are blamed for not 
understanding the machine, for not following its rigid specifica-
tions. With everyday objects, the result is frustration. With complex 
devices and commercial and industrial processes, the resulting 
difficulties can lead to accidents, injuries, and even deaths. It is 
time to reverse the situation: to cast the blame upon the machines 
and their design. It is the machine and its design that are at fault. It 
is the duty of machines and those who design them to understand 
people. It is not our duty to understand the arbitrary, meaningless 
dictates of machines.
The reasons for the deficiencies in human-machine interaction 
are numerous. Some come from the limitations of today’s technol-
ogy. Some come from self-imposed restrictions by the designers, 
often to hold down cost. But most of the problems come from a 
complete lack of understanding of the design principles necessary 
for effective human-machine interaction. Why this deficiency? Be-
cause much of the design is done by engineers who are experts 
in technology but limited in their understanding of people. “We 
are people ourselves,” they think, “so we understand people.” But 
in fact, we humans are amazingly complex. Those who have not 
studied human behavior often think it is pretty simple. Engineers, 
moreover, make the mistake of thinking that logical explanation is 
sufficient: “If only people would read the instructions,” they say, 
“everything would be all right.”
Engineers are trained to think logically. As a result, they come to 
believe that all people must think this way, and they design their 
machines accordingly. When people have trouble, the engineers 
are upset, but often for the wrong reason. “What are these people 
doing?” they will wonder. “Why are they doing that?” The prob-
lem with the designs of most engineers is that they are too logical. 
We have to accept human behavior the way it is, not the way we 
would wish it to be.
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 one: The Psychopathology of Everyday Things 7
I used to be an engineer, focused upon technical requirements, 
quite ignorant of people. Even after I switched into psychology 
and cognitive science, I still maintained my engineering emphasis 
upon logic and mechanism. It took a long time for me to realize 
that my understanding of human behavior was relevant to my in-
terest in the design of technology. As I watched people struggle 
with technology, it became clear that the difficulties were caused 
by the technology, not the people.
I was called upon to help analyze the American nuclear power 
plant accident at Three Mile Island (the island name comes from 
the fact that it is located on a river, three miles south of Middle-
town in the state of Pennsylvania). In this incident, a rather simple 
mechanical failure was misdiagnosed. This led to several days of 
difficulties and confusion, total destruction of the reactor, and a 
very close call to a severe radiation release, all of which brought 
the American nuclear power industry to a complete halt. The op-
erators were blamed for these failures: “human error” was the im-
mediate analysis. But the committee I was on discovered that the 
plant’s control rooms were so poorly designed that error was inevi-
table: design was at fault, not the operators. The moral was simple: 
we were designing things for people, so we needed to understand 
both technology and people. But that’s a difficult step for many 
engineers: machines are so logical, so orderly. If we didn’t have 
people, everything would work so much better. Yup, that’s how I 
used to think.
My work with that committee changed my view of design. To-
day, I realize that design presents afascinating interplay of tech-
nology and psychology, that the designers must understand both. 
Engineers still tend to believe in logic. They often explain to me 
in great, logical detail, why their designs are good, powerful, and 
wonderful. “Why are people having problems?” they wonder. 
“You are being too logical,” I say. “You are designing for people the 
way you would like them to be, not for the way they really are.”
When the engineers object, I ask whether they have ever made 
an error, perhaps turning on or off the wrong light, or the wrong 
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8 The Design of Everyday Things
stove burner. “Oh yes,” they say, “but those were errors.” That’s 
the point: even experts make errors. So we must design our ma-
chines on the assumption that people will make errors. (Chapter 5 
provides a detailed analysis of human error.)
Human-Centered Design
People are frustrated with everyday things. From the ever-increasing 
complexity of the automobile dashboard, to the increasing auto-
mation in the home with its internal networks, complex music, 
video, and game systems for entertainment and communication, 
and the increasing automation in the kitchen, everyday life some-
times seems like a never-ending fight against confusion, continued 
errors, frustration, and a continual cycle of updating and maintain-
ing our belongings.
In the multiple decades that have elapsed since the first edition 
of this book was published, design has gotten better. There are now 
many books and courses on the topic. But even though much has 
improved, the rapid rate of technology change outpaces the ad-
vances in design. New technologies, new applications, and new 
methods of interaction are continually arising and evolving. New 
industries spring up. Each new development seems to repeat the 
mistakes of the earlier ones; each new field requires time before 
it, too, adopts the principles of good design. And each new inven-
tion of technology or interaction technique requires experimenta-
tion and study before the principles of good design can be fully 
integrated into practice. So, yes, things are getting better, but as a 
result, the challenges are ever present.
The solution is human-centered design (HCD), an approach 
that puts human needs, capabilities, and behavior first, then de-
signs to accommodate those needs, capabilities, and ways of be-
having. Good design starts with an understanding of psychology 
and technology. Good design requires good communication, espe-
cially from machine to person, indicating what actions are possible, 
what is happening, and what is about to happen. Communica-
tion is especially important when things go wrong. It is relatively 
easy to design things that work smoothly and harmoniously as 
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 one: The Psychopathology of Everyday Things 9
long as things go right. But as soon as there is a problem or a mis-
understanding, the problems arise. This is where good design 
is essential. Designers need to focus their attention on the cases 
where things go wrong, not just on when things work as planned. 
Actually, this is where the most satisfaction can arise: when some-
thing goes wrong but the machine highlights the problems, then 
the person understands the issue, takes the proper actions, and the 
problem is solved. When this happens smoothly, the collaboration 
of person and device feels wonderful.
Human-centered design is a design philosophy. It means start-
ing with a good understanding of people and the needs that the 
design is intended to meet. This understanding comes about pri-
marily through observation, for people themselves are often un-
aware of their true needs, even unaware of the difficulties they are 
encountering. Getting the specification of the thing to be defined 
is one of the most difficult parts of the design, so much so that the 
HCD principle is to avoid specifying the problem as long as pos-
sible but instead to iterate upon repeated approximations. This is 
done through rapid tests of ideas, and after each test modifying the 
approach and the problem definition. The results can be products 
that truly meet the needs of people. Doing HCD within the rigid 
time, budget, and other constraints of industry can be a challenge: 
Chapter 6 examines these issues.
Where does HCD fit into the earlier discussion of the several dif-
ferent forms of design, especially the areas called industrial, inter-
action, and experience design? These are all compatible. HCD is a 
philosophy and a set of procedures, whereas the others are areas of 
focus (see Table 1.1). The philosophy and procedures of HCD add 
Experience design
Industrial design These are areas of focus
Interaction design
Human-centered design The process that ensures that the 
designs match the needs and capa-
bilities of the people for whom they 
are intended
TABLE 1.1. The Role of HCD and Design Specializations
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10 The Design of Everyday Things
deep consideration and study of human needs to the design pro-
cess, whatever the product or service, whatever the major focus.
Fundamental Principles of Interaction
Great designers produce pleasurable experiences. Experience: note 
the word. Engineers tend not to like it; it is too subjective. But when 
I ask them about their favorite automobile or test equipment, they 
will smile delightedly as they discuss the fit and finish, the sensa-
tion of power during acceleration, their ease of control while shift-
ing or steering, or the wonderful feel of the knobs and switches on 
the instrument. Those are experiences.
Experience is critical, for it determines how fondly people re-
member their interactions. Was the overall experience positive, or 
was it frustrating and confusing? When our home technology be-
haves in an uninterpretable fashion we can become confused, frus-
trated, and even angry—all strong negative emotions. When there 
is understanding it can lead to a feeling of control, of mastery, and 
of satisfaction or even pride—all strong positive emotions. Cog-
nition and emotion are tightly intertwined, which means that the 
designers must design with both in mind.
When we interact with a product, we need to figure out how to 
work it. This means discovering what it does, how it works, and 
what operations are possible: discoverability. Discoverability re-
sults from appropriate application of five fundamental psycholog-
ical concepts covered in the next few chapters: affordances, signifiers, 
constraints, mappings, and feedback. But there is a sixth principle, 
perhaps most important of all: the conceptual model of the system. 
It is the conceptual model that provides true understanding. So 
I now turn to these fundamental principles, starting with affor-
dances, signifiers, mappings, and feedback, then moving to con-
ceptual models. Constraints are covered in Chapters 3 and 4.
AFFORDANCES
We live in a world filled with objects, many natural, the rest artifi-
cial. Every day we encounter thousands of objects, many of them 
new to us. Many of the new objects are similar to ones we already 
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 one: The Psychopathology of Everyday Things 11
know, but many are unique, yet we manage quite well. How do we 
do this? Why is it that when we encounter many unusual natural 
objects, we know how to interact with them? Why is this true with 
many of the artificial, human-made objects we encounter? The an-
swer lies with a few basic principles. Some of the most important 
of these principles come from a consideration of affordances.
The term affordance refers to the relationship between a physi-
cal object anda person (or for that matter, any interacting agent, 
whether animal or human, or even machines and robots). An affor-
dance is a relationship between the properties of an object and the 
capabilities of the agent that determine just how the object could 
possibly be used. A chair affords (“is for”) support and, therefore, 
affords sitting. Most chairs can also be carried by a single per-
son (they afford lifting), but some can only be lifted by a strong 
person or by a team of people. If young or relatively weak people 
cannot lift a chair, then for these people, the chair does not have 
that affordance, it does not afford lifting.
The presence of an affordance is jointly determined by the qual-
ities of the object and the abilities of the agent that is interacting. 
This relational definition of affordance gives considerable difficulty 
to many people. We are used to thinking that properties are asso-
ciated with objects. But affordance is not a property. An affordance 
is a relationship. Whether an affordance exists depends upon the 
properties of both the object and the agent.
Glass affords transparency. At the same time, its physical struc-
ture blocks the passage of most physical objects. As a result, glass 
affords seeing through and support, but not the passage of air or 
most physical objects (atomic particles can pass through glass). 
The blockage of passage can be considered an anti-affordance—the 
prevention of interaction. To be effective, affordances and anti-
affordances have to be discoverable—perceivable. This poses a 
difficulty with glass. The reason we like glass is its relative invis-
ibility, but this aspect, so useful in the normal window, also hides 
its anti-affordance property of blocking passage. As a result, birds 
often try to fly through windows. And every year, numerous peo-
ple injure themselves when they walk (or run) through closed glass 
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12 The Design of Everyday Things
doors or large picture windows. If an affordance or anti-affordance 
cannot be perceived, some means of signaling its presence is re-
quired: I call this property a signifier (discussed in the next section).
The notion of affordance and the insights it provides originated 
with J. J. Gibson, an eminent psychologist who provided many 
advances to our understanding of human perception. I had in-
teracted with him over many years, sometimes in formal confer-
ences and seminars, but most fruitfully over many bottles of beer, 
late at night, just talking. We disagreed about almost everything. 
I was an engineer who became a cognitive psychologist, trying to 
understand how the mind works. He started off as a Gestalt psy-
chologist, but then developed an approach that is today named 
after him: Gibsonian psychology, an ecological approach to percep-
tion. He argued that the world contained the clues and that people 
simply picked them up through “direct perception.” I argued that 
nothing could be direct: the brain had to process the information 
arriving at the sense organs to put together a coherent interpreta-
tion. “Nonsense,” he loudly proclaimed; “it requires no interpreta-
tion: it is directly perceived.” And then he would put his hand to 
his ears, and with a triumphant flourish, turn off his hearing aids: 
my counterarguments would fall upon deaf ears—literally.
When I pondered my question—how do people know how to act 
when confronted with a novel situation—I realized that a large 
part of the answer lay in Gibson’s work. He pointed out that all the 
senses work together, that we pick up information about the world 
by the combined result of all of them. “Information pickup” was one 
of his favorite phrases, and Gibson believed that the combined in-
formation picked up by all of our sensory apparatus—sight, sound, 
smell, touch, balance, kinesthetic, acceleration, body position—
determines our perceptions without the need for internal pro-
cessing or cognition. Although he and I disagreed about the role 
played by the brain’s internal processing, his brilliance was in fo-
cusing attention on the rich amount of information present in the 
world. Moreover, the physical objects conveyed important infor-
mation about how people could interact with them, a property he 
named “affordance.”
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 one: The Psychopathology of Everyday Things 13
Affordances exist even if they are not visible. For designers, their 
visibility is critical: visible affordances provide strong clues to the 
operations of things. A flat plate mounted on a door affords push-
ing. Knobs afford turning, pushing, and pulling. Slots are for in-
serting things into. Balls are for throwing or bouncing. Perceived 
affordances help people figure out what actions are possible with-
out the need for labels or instructions. I call the signaling compo-
nent of affordances signifiers.
SIGNIFIERS
Are affordances important to designers? The first edition of this 
book introduced the term affordances to the world of design. The 
design community loved the concept and affordances soon prop-
agated into the instruction and writing about design. I soon found 
mention of the term everywhere. Alas, the term became used in 
ways that had nothing to do with the original.
Many people find affordances difficult to understand because 
they are relationships, not properties. Designers deal with fixed 
properties, so there is a temptation to say that the property is an 
affordance. But that is not the only problem with the concept of 
affordances.
Designers have practical problems. They need to know how to 
design things to make them understandable. They soon discov-
ered that when working with the graphical designs for electronic 
displays, they needed a way to designate which parts could be 
touched, slid upward, downward, or sideways, or tapped upon. 
The actions could be done with a mouse, stylus, or fingers. Some 
systems responded to body motions, gestures, and spoken words, 
with no touching of any physical device. How could designers de-
scribe what they were doing? There was no word that fit, so they 
took the closest existing word—affordance. Soon designers were 
saying such things as, “I put an affordance there,” to describe why 
they displayed a circle on a screen to indicate where the person 
should touch, whether by mouse or by finger. “No,” I said, “that is not 
an affordance. That is a way of communicating where the touch 
should be. You are communicating where to do the touching: the 
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14 The Design of Everyday Things
affordance of touching exists on the entire screen: you are trying to 
signify where the touch should take place. That’s not the same thing 
as saying what action is possible.”
Not only did my explanation fail to satisfy the design commu-
nity, but I myself was unhappy. Eventually I gave up: designers 
needed a word to describe what they were doing, so they chose 
affordance. What alternative did they have? I decided to provide a 
better answer: signifiers. Affordances determine what actions are 
possible. Signifiers communicate where the action should take place. 
We need both.
People need some way of understanding the product or service 
they wish to use, some sign of what it is for, what is happening, 
and what the alternative actions are. People search for clues, for 
any sign that might help them cope and understand. It is the sign 
that is important, anything that might signify meaningful informa-
tion. Designers need to provide these clues. What people need, and 
what designers must provide, are signifiers. Good design requires, 
among other things, good communication of the purpose, struc-
ture, and operation of the device tothe people who use it. That is 
the role of the signifier.
The term signifier has had a long and illustrious career in the ex-
otic field of semiotics, the study of signs and symbols. But just as 
I appropriated affordance to use in design in a manner somewhat 
different than its inventor had intended, I use signifier in a some-
what different way than it is used in semiotics. For me, the term 
signifier refers to any mark or sound, any perceivable indicator that 
communicates appropriate behavior to a person.
Signifiers can be deliberate and intentional, such as the sign 
push on a door, but they may also be accidental and unintentional, 
such as our use of the visible trail made by previous people walk-
ing through a field or over a snow-covered terrain to determine 
the best path. Or how we might use the presence or absence of 
people waiting at a train station to determine whether we have 
missed the train. (I explain these ideas in more detail in my book 
Living with Complexity.)
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 one: The Psychopathology of Everyday Things 15
FIGURE 1.2 . Problem Doors: Signifiers Are Needed. Door hardware 
can signal whether to push or pull without signs, but the hardware of the 
two doors in the upper photo, A, are identical even though one should be 
pushed, the other pulled. The flat, ribbed horizontal bar has the obvious 
perceived affordance of pushing, but as the signs indicate, the door on the 
left is to be pulled, the one on the right is to be pushed. In the bottom pair of 
photos, B and C, there are no visible signifiers or affordances. How does one 
know which side to push? Trial and error. When external signifiers—signs—
have to be added to something as simple as a door, it indicates bad design. 
(Photographs by the author.)
The signifier is an important communication device to the recipi-
ent, whether or not communication was intended. It doesn’t matter 
whether the useful signal was deliberately placed or whether it is 
incidental: there is no necessary distinction. Why should it matter 
whether a flag was placed as a deliberate clue to wind direction (as 
is done at airports or on the masts of sailboats) or was there as an 
A.
B. C.
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16 The Design of Everyday Things
advertisement or symbol of pride in one’s country (as is done on 
public buildings). Once I interpret a flag’s motion to indicate wind 
direction, it does not matter why it was placed there.
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. Most readers have learned to use 
this accidental signifier to aid in their enjoyment of the reading. 
With few pages left, we know the end is near. And if the reading is 
torturous, as in a school assignment, one can always console one-
self by knowing there are “only a few more pages to get through.” 
Electronic book readers do not have the physical structure of paper 
books, so unless the software designer deliberately provides a clue, 
they do not convey any signal about the amount of text remaining.
FIGURE 1.3. Sliding Doors: Seldom Done Well. Sliding doors are seldom signified 
properly. The top two photographs show the sliding door to the toilet on an Amtrak 
train in the United States. The handle clearly signifies “pull,” but in fact, it needs to be 
rotated and the door slid to the right. The owner of the store in Shanghai, China, Photo 
C, solved the problem with a sign. “don’t push!” it says, in both English and Chinese. 
Amtrak’s toilet door could have used a similar kind of sign. (Photographs by the author.) 
A. B.
C.
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 one: The Psychopathology of Everyday Things 17
Whatever their nature, planned or accidental, signifiers provide 
valuable clues as to the nature of the world and of social activities. 
For us to function in this social, technological world, we need to 
develop internal models of what things mean, of how they operate. 
We seek all the clues we can find to help in this enterprise, and 
in this way, we are detectives, searching for whatever guidance 
we might find. If we are fortunate, thoughtful designers provide 
the clues for us. Otherwise, we must use our own creativity and 
imagination.
FIGURE 1.4. The Sink That Would Not Drain: Where Signifiers Fail. I washed my 
hands in my hotel sink in London, but then, as shown in Photo A, was left with the 
question of how to empty the sink of the dirty water. I searched all over for a control: 
none. I tried prying open the sink stopper with a spoon (Photo B): failure. I finally left 
my hotel room and went to the front desk to ask for instructions. (Yes, I actually did.) 
“Push down on the stopper,” I was told. Yes, it worked (Photos C and D). But how was 
anyone to ever discover this? And why should I have to put my clean hands back into 
the dirty water to empty the sink? The problem here is not just the lack of signifier, it is 
the faulty decision to produce a stopper that requires people to dirty their clean hands 
to use it. (Photographs by the author.)
A. B.
C. D.
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18 The Design of Everyday Things
Affordances, perceived affordances, and signifiers have much in 
common, so let me pause to ensure that the distinctions are clear.
Affordances represent the possibilities in the world for how an 
agent (a person, animal, or machine) can interact with something. 
Some affordances are perceivable, others are invisible. Signifiers 
are signals. Some signifiers are signs, labels, and drawings placed 
in the world, such as the signs labeled “push,” “pull,” or “exit” 
on doors, or arrows and diagrams indicating what is to be acted 
upon or in which direction to gesture, or other instructions. Some 
signifiers are simply the perceived affordances, such as the han-
dle of a door or the physical structure of a switch. Note that some 
perceived affordances may not be real: they may look like doors 
or places to push, or an impediment to entry, when in fact they 
are not. These are misleading signifiers, oftentimes accidental but 
sometimes purposeful, as when trying to keep people from doing 
actions for which they are not qualified, or in games, where one of 
the challenges is to figure out what is real and what is not.
FIGURE 1.5. Accidental Affordances 
Can Become Strong Signifiers. This 
wall, at the Industrial Design department 
of KAIST, in Korea, provides an anti-
affordance, preventing people from falling 
down the stair shaft. Its top is flat, an ac-
cidental by-product of the design. But flat 
surfaces afford support, and as soon as one 
person discovers it can be used to dispose 
of empty drink containers, the discarded 
container becomes a signifier, telling others 
that it is permissible to discard their items 
there. (Photographs by the author.)
A.
C.B.
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 one: The Psychopathology of Everyday Things 19
My favorite example of a misleading signifier is a row of ver-
tical pipes across a service road that I once saw in a public park. 
The pipes obviously blocked cars and trucks from driving on that 
road: they were good examples of anti-affordances. But to my great 
surprise, I saw a park vehicle simply go through the pipes. Huh? I 
walked over and examined them: the pipes were made of rubber, 
so vehicles could simply drive right over them. A very clever sig-
nifier, signaling a blocked road (via an apparent anti-affordance) 
to the average person, but permitting passage for those who knew.
Tosummarize:
• Affordances are the possible interactions between people and the en-
vironment. Some affordances are perceivable, others are not.
• Perceived affordances often act as signifiers, but they can be ambiguous.
• Signifiers signal things, in particular what actions are possible and 
how they should be done. Signifiers must be perceivable, else they 
fail to function.
In design, signifiers are more important than affordances, for 
they communicate how to use the design. A signifier can be words, 
a graphical illustration, or just a device whose perceived affor-
dances are unambiguous. Creative designers incorporate the sig-
nifying part of the design into a cohesive experience. For the most 
part, designers can focus upon signifiers.
Because affordances and signifiers are fundamentally important 
principles of good design, they show up frequently in the pages of 
this book. Whenever you see hand-lettered signs pasted on doors, 
switches, or products, trying to explain how to work them, what to 
do and what not to do, you are also looking at poor design.
A F F OR DA NC E S A N D SIGN I F I E R S : A C ON V E R SAT ION
A designer approaches his mentor. He is working on a system that 
recommends restaurants to people, based upon their preferences 
and those of their friends. But in his tests, he discovered that peo-
ple never used all of the features. “Why not?” he asks his mentor.
(With apologies to Socrates.)
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20 The Design of Everyday Things
DESIGNER
I’m frustrated; people aren’t using 
our application properly.
The screen shows the restaurant 
that we recommend. It matches their 
preferences, and their friends like 
it as well. If they want to see other 
recommendations, all they have to 
do is swipe left or right. To learn 
more about a place, just swipe up for 
a menu or down to see if any friends 
are there now. People seem to find 
the other recommendations, but not 
the menus or their friends? I don’t 
understand.
I don’t know. Should I add some 
affordances? Suppose I put an arrow 
on each edge and add a label saying 
what they do.
Yes, you have a point. But the affor-
dances weren’t visible. I made them 
visible.
Yes, isn’t that what I said?
Oh, I see. But then why do designers 
care about affordances? Perhaps 
we should focus our attention on 
signifiers.
Oh. Now I understand my confusion. 
Yes, a signifier is what signifies. It 
is a sign. Now it seems perfectly 
obvious.
MENTOR
Can you tell me about it?
Why do you think this might be?
That is very nice. But why do you 
call these affordances? They could 
already do the actions. Weren’t the 
affordances already there?
Very true. You added a signal of 
what to do.
Not quite—you called them affor-
dances even though they afford 
nothing new: they signify what to do 
and where to do it. So call them by 
their right name: “signifiers.”
You speak wisely. Communication is 
a key to good design. And a key to 
communication is the signifier.
Profound ideas are always obvious 
once they are understood.
MAPPING
Mapping is a technical term, borrowed from mathematics, mean-
ing the relationship between the elements of two sets of things. 
Suppose there are many lights in the ceiling of a classroom or au-
ditorium and a row of light switches on the wall at the front of the 
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 one: The Psychopathology of Everyday Things 21
room. The mapping of switches to lights specifies which switch 
controls which light.
Mapping is an important concept in the design and layout of 
controls and displays. When the mapping uses spatial correspon-
dence between the layout of the controls and the devices being 
controlled, it is easy to determine how to use them. In steering a 
car, we rotate the steering wheel clockwise to cause the car to turn 
right: the top of the wheel moves in the same direction as the car. 
Note that other choices could have been made. In early cars, steer-
ing was controlled by a variety of devices, including tillers, han-
dlebars, and reins. Today, some vehicles use joysticks, much as in a 
computer game. In cars that used tillers, steering was done much 
as one steers a boat: move the tiller to the left to turn to the right. 
Tractors, construction equipment such as bulldozers and cranes, 
and military tanks that have tracks instead of wheels use separate 
controls for the speed and direction of each track: to turn right, the 
left track is increased in speed, while the right track is slowed or 
even reversed. This is also how a wheelchair is steered.
All of these mappings for the control of vehicles work because 
each has a compelling conceptual model of how the operation of 
the control affects the vehicle. Thus, if we speed up the left wheel 
of a wheelchair while stopping the right wheel, it is easy to imag-
ine the chair’s pivoting on the right wheel, circling to the right. In 
FIGURE 1.6. Signifiers on a Touch Screen. 
The arrows and icons are signifiers: they pro-
vide signals about the permissible operations 
for this restaurant guide. Swiping left or right 
brings up new restaurant recommendations. 
Swiping up reveals the menu for the restau-
rant being displayed; swiping down, friends 
who recommend the restaurant.
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22 The Design of Everyday Things
a small boat, we can understand the tiller by realizing that pushing 
the tiller to the left causes the ship’s rudder to move to the right 
and the resulting force of the water on the rudder slows down the 
right side of the boat, so that the boat rotates to the right. It doesn’t 
matter whether these conceptual models are accurate: what mat-
ters is that they provide a clear way of remembering and under-
standing the mappings. The relationship between a control and 
its results is easiest to learn wherever there is an understandable 
mapping between the controls, the actions, and the intended result.
Natural mapping, by which I mean taking advantage of spatial 
analogies, leads to immediate understanding. For example, to move 
an object up, move the control up. To make it easy to determine 
which control works which light in a large room or auditorium, 
arrange the controls in the same pattern as the lights. Some natural 
mappings are cultural or biological, as in the universal standard 
that moving the hand up signifies more, moving it down signifies 
less, which is why it is appropriate to use vertical position to rep-
resent intensity or amount. Other natural mappings follow from 
the principles of perception and allow for the natural grouping or 
patterning of controls and feedback. Groupings and proximity 
are important principles from Gestalt psychology that can be used 
to map controls to function: related controls should be grouped to-
gether. Controls should be close to the item being controlled.
Note that there are many mappings that feel “natural” but in fact 
are specific to a particular culture: what is natural for one culture 
is not necessarily natural for another. In Chapter 3, I discuss how 
FIGURE 1.7. Good Mapping: Automobile Seat 
Adjustment Control. This is an excellent example of 
natural mapping. The control is in the shape of the 
seat itself: the mapping is straightforward. To move 
the front edge of the seat higher, lift up on the front 
part of the button. To make the seat back recline, 
move the button back. The same principle could be 
applied to much more common objects. This partic-
ular control is from Mercedes-Benz, but this form of 
mapping is now used by many automobile compa-
nies. (Photograph by the author.)
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 one: The Psychopathology of Everyday Things 23
different culturesview time, which has important implications for 
some kinds of mappings.
A device is easy to use when the set of possible actions is visi-
ble, when the controls and displays exploit natural mappings. The 
principles are simple but rarely incorporated into design. Good de-
sign takes care, planning, thought, and an understanding of how 
people behave.
FEEDBACK
Ever watch people at an elevator repeatedly push the Up button, 
or repeatedly push the pedestrian button at a street crossing? Ever 
drive to a traffic intersection and wait an inordinate amount of 
time for the signals to change, wondering all the time whether the 
detection circuits noticed your vehicle (a common problem with 
bicycles)? What is missing in all these cases is feedback: some way 
of letting you know that the system is working on your request.
Feedback—communicating the results of an action—is a well-
known concept from the science of control and information theory. 
Imagine trying to hit a target with a ball when you cannot see the 
target. Even as simple a task as picking up a glass with the hand re-
quires feedback to aim the hand properly, to grasp the glass, and to 
lift it. A misplaced hand will spill the contents, too hard a grip will 
break the glass, and too weak a grip will allow it to fall. The human 
nervous system is equipped with numerous feedback mechanisms, 
including visual, auditory, and touch sensors, as well as vestibular 
and proprioceptive systems that monitor body position and mus-
cle and limb movements. Given the importance of feedback, it is 
amazing how many products ignore it.
Feedback must be immediate: even a delay of a tenth of a second 
can be disconcerting. If the delay is too long, people often give up, 
going off to do other activities. This is annoying to the people, but 
it can also be wasteful of resources when the system spends con-
siderable time and effort to satisfy the request, only to find that the 
intended recipient is no longer there. Feedback must also be infor-
mative. Many companies try to save money by using inexpensive 
lights or sound generators for feedback. These simple light flashes 
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24 The Design of Everyday Things
or beeps are usually more annoying than useful. They tell us that 
something has happened, but convey very little information about 
what has happened, and then nothing about what we should do 
about it. When the signal is auditory, in many cases we cannot 
even be certain which device has created the sound. If the signal 
is a light, we may miss it unless our eyes are on the correct spot 
at the correct time. Poor feedback can be worse than no feedback 
at all, because it is distracting, uninformative, and in many cases 
irritating and anxiety-provoking.
Too much feedback can be even more annoying than too little. 
My dishwasher likes to beep at three a.m. to tell me that the wash 
is done, defeating my goal of having it work in the middle of the 
night so as not to disturb anyone (and to use less expensive elec-
tricity). But worst of all is inappropriate, uninterpretable feedback. 
The irritation caused by a “backseat driver” is well enough known 
that it is the staple of numerous jokes. Backseat drivers are often 
correct, but their remarks and comments can be so numerous and 
continuous that instead of helping, they become an irritating dis-
traction. Machines that give too much feedback are like backseat 
drivers. Not only is it distracting to be subjected to continual flash-
ing lights, text announcements, spoken voices, or beeps and boops, 
but it can be dangerous. Too many announcements cause people to 
ignore all of them, or wherever possible, disable all of them, which 
means that critical and important ones are apt to be missed. Feed-
back is essential, but not when it gets in the way of other things, 
including a calm and relaxing environment.
Poor design of feedback can be the result of decisions aimed at 
reducing costs, even if they make life more difficult for people. 
Rather than use multiple signal lights, informative displays, or 
rich, musical sounds with varying patterns, the focus upon cost 
reduction forces the design to use a single light or sound to convey 
multiple types of information. If the choice is to use a light, then 
one flash might mean one thing; two rapid flashes, something else. 
A long flash might signal yet another state; and a long flash fol-
lowed by a brief one, yet another. If the choice is to use a sound, 
quite often the least expensive sound device is selected, one that 
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 one: The Psychopathology of Everyday Things 25
can only produce a high-frequency beep. Just as with the lights, 
the only way to signal different states of the machine is by beeping 
different patterns. What do all these different patterns mean? How 
can we possibly learn and remember them? It doesn’t help that 
every different machine uses a different pattern of lights or beeps, 
sometimes with the same patterns meaning contradictory things 
for different machines. All the beeps sound alike, so it often isn’t 
even possible to know which machine is talking to us.
Feedback has to be planned. All actions need to be confirmed, 
but in a manner that is unobtrusive. Feedback must also be prior-
itized, so that unimportant information is presented in an unob-
trusive fashion, but important signals are presented in a way that 
does capture attention. When there are major emergencies, then 
even important signals have to be prioritized. When every device 
is signaling a major emergency, nothing is gained by the result-
ing cacophony. The continual beeps and alarms of equipment can 
be dangerous. In many emergencies, workers have to spend valu-
able time turning off all the alarms because the sounds interfere 
with the concentration required to solve the problem. Hospital op-
erating rooms, emergency wards. Nuclear power control plants. 
Airplane cockpits. All can become confusing, irritating, and life-
endangering places because of excessive feedback, excessive alarms, 
and incompatible message coding. Feedback is essential, but it has 
to be done correctly. Appropriately.
CONCEPTUAL MODELS
A conceptual model is an explanation, usually highly simplified, 
of how something works. It doesn’t have to be complete or even 
accurate as long as it is useful. The files, folders, and icons you see 
displayed on a computer screen help people create the conceptual 
model of documents and folders inside the computer, or of apps 
or applications residing on the screen, waiting to be summoned. In 
fact, there are no folders inside the computer—those are effective 
conceptualizations designed to make them easier to use. Some-
times these depictions can add to the confusion, however. When 
reading e-mail or visiting a website, the material appears to be on 
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26 The Design of Everyday Things
the device, for that is where it is displayed and manipulated. But 
in fact, in many cases the actual material is “in the cloud,” located 
on some distant machine. The conceptual model is of one, coherent 
image, whereas it may actually consist of parts, each located on 
different machines that could be almost anywhere in the world. 
This simplified model is helpful for normal usage, but if the net-
work connection to the cloud services is interrupted, the result can 
be confusing. Information is still on their screen, but users can no 
longer save it or retrieve new things: their conceptual model offers 
no explanation. Simplified models are valuable only as long as the 
assumptions that support them hold true.
There are often multiple conceptual models of a product or de-
vice.