1990 and 2002 (The Psychology of Everyday Things editions with new forewords) The Design of Everyday Things. A Comprehensive Strategy for Better Reading: Cognition and Emotion, 2010. with Masanori Okimoto; my essays, with comments in japanese, are used for teaching english as . second language for Japanese speakers) Living with Complexity, 2011. No part of this book may be reproduced in any form without written permission, except in the case of brief quotations embodied in articles and critical reviews.
Books published by Basic Books are available at special discounts for bulk purchases in the United States by corporations, institutions and other organizations. How People Do Things: The Waves of Execution and Evaluation The Seven Stages of Action. The trade-off between knowledge in the world and in main memory in multiple heads, multiple devices.
PREFACE TO THE REVISED EDITION
It has been assigned on courses and handed out as required reading in many companies. I'm happy with the response and the number of people corresponding with me about it, sending me further examples of thoughtless, crazy design, plus the occasional example of great design. Many readers have told me that it has changed their lives and made them more sensitive to life's problems and people's needs.
Why a Revised Edition?
To understand products, it is not enough to understand design or technology: it is essential to understand business.
What Has Changed?
- The Psychopathology of Everyday Things
- The Psychology of Everyday Actions
- Knowledge in the Head and in the World
- Human Error? No, Bad Design
- Design Thinking
- Design in the World of Business
I am updating the classification of errors to reflect progress since the publication of the first edition. I show the relationship between the classification of errors, mistakes and mistakes and the seven-stage model of action, something new in this revision. The chapter concludes with a brief discussion of the problems that automation brings (from my book The Design of Future Things) and what I consider to be the best new approach to dealing with design to eliminate or minimize human error: resilience engineering.
I discuss the challenges of designing in a company where schedules, budgets, and the competing demands of various departments provide serious limits on what can be accomplished. The chapter concludes with a discussion of the role of standards (modified from a similar discussion in the previous edition) and some more general design guidelines. The chapter concludes with discussions of upcoming trends, the future of books, the moral responsibilities of design, and the rise of small DIYers, who are beginning to change the way ideas are conceived and brought to market: "the rise of the small," I call it.
Summary
THE PSYCHOPATHOLOGY OF EVERYDAY THINGS
Why do they do that?” The problem with most engineers' designs is that they are too logical. But there is a sixth principle, perhaps the most important: the conceptual model of the system. The mapping between holes and fingers – the set of possible operations – is indicated and limited by the holes.
The conceptual model A is provided by the system image of the refrigerator as obtained from the controls. The designer's conceptual model is the designer's conception of the look, feel and operation of a product. There was a reasonable relationship between the turning of the knob and the resulting turning of the hands.
THE PSYCHOLOGY OF EVERYDAY ACTIONS
This is the planning phase that determines which of the many possible plans of action to follow. After we specify what actions to perform, we must actually perform them - the stages of execution. This is a case of event-driven behavior: the sequence starts with the world, which causes the evaluation of the state and the formulation of a goal.
Although this is a gross oversimplification of the actual processing, it is a good enough approximation to provide guidance in understanding human behavior. This is sometimes called the "lizard brain". All humans have the same basic visceral responses. Although we are usually aware of our actions, we are often unaware of the details.
The behavioral level is about expectations, so it is sensitive to the expectations of the action sequence and then the interpretations of the reactions. In the absence of external information, people can let their imaginations run free as long as the conceptual models they develop are grounded. the facts as they perceive them. More and more often the blame is attributed to "human error". The person involved can be fined, punished or fired.
Both A and B help the resident to develop conceptual models of the thermostat and the home's energy consumption. Each of the seven stages indicates a place where the person using the system has a question. It is possible to determine which actions are possible and the current state of the device.
There is complete and continuous information about the results of actions and the current state of the product or service.
KNOWLEDGE IN THE HEAD AND IN THE WORLD
Much of the knowledge a person needs to do a task can be derived from the information in the world. Behavior is determined by combining the knowledge in the head with that in the world. Combine the two, knowledge in the head and in the world, and performance is even better.
Because so much knowledge is available in the environment, it is surprising how little we have to learn. Signifiers, physical constraints, and natural mappings are all perceptible cues that function as knowledge in the world. All it takes is the combination of knowledge in the world and in the head that makes decisions clear.
Perhaps a better way to make memory unnecessary is to put the required information in the world. They don't have to be exact as long as they lead to the correct behavior in the desired situation. Knowledge in the world and knowledge in the head are indispensable in our daily activities.
Knowledge in the head is efficient: no search and interpretation of the environment is required. How easy it is to interpret knowledge in the world depends on the skill of the designer. As we have just discussed, reminders provide a good example of the relative tradeoffs between knowledge in the world versus in the head.
Mapping, a topic in Chapter 1, provides a good example of the power of combining knowledge in the world with that in the head. With stove controls it is of course not possible to place the controls directly on the burners. With good natural mapping, the relationship between the controls and the burner is fully contained within the world; the burden on human memory is much reduced.
KNOWING WHAT TO DO: CONSTRAINTS, DISCOVERABILITY, AND FEEDBACK
A third option is to design the shape of the battery so that it can only fit in one way. As a result, it is no longer as easy as it used to be to identify that the yellow piece represents the headlight on the front of the motorcycle. In the case of a motorcycle, there is only one important location for the rider, who must sit facing forward.
If the orientation of the lights and switches are different, the natural mapping is destroyed. Since the glass allows the internal shelves to be transparent, it is obvious that there is no room to open the door inwards. With six light switches mounted in a one-dimensional array, vertically on the wall, there is no way it could naturally map to a two-dimensional, horizontal arrangement of lights in the ceiling.
Match the layout of the lights with the layout of the switches: the principle of natural mapping. Starting a car has an imperative function associated with it - the driver must have a physical object signifying permission to use the car. Because the vehicle will not start without the authorization proven by possession of the key, it is a mandatory feature.
It is the marker component of perceived coping that allows people to determine possible actions. The merits of the new system are irrelevant: it is the change that is worrying. One of the virtues of sounds is that they can be detected even when attention is elsewhere.
One way to overcome the fear of the new is to make it look like the old.
HUMAN ERROR? NO, BAD DESIGN
But when someone says, "It was my fault, I knew better," that's not a valid analysis of the problem. Errors can be understood by reference to the seven stages of the action cycle of Chapter 2 (Figure 5.2). Slips occur in the execution of a plan, or in the perception or interpretation of the outcome - the lower stages.
Out of memory can occur at any of the eight transitions between phases, shown by X in Figure 5.2B. The study of slips is the study of the psychology of everyday mistakes—what Freud called the "psychopathology of everyday life." Once the situation has been classified, choosing the appropriate rule is often straightforward.
This is difficult to detect because there is usually significant evidence supporting the misclassification of the situation and choice of rule. This is especially true in situations where mistakes were made in diagnosing the problem. Sometimes simply asking one or more team members to take a break for a few hours can lead to the same new analysis (although convincing someone in an emergency situation to stop for a few hours is understandably difficult).
Trusting in the ability of the first person, the controller often does a quick, less than thorough job. For example, in aviation, one of the steps is to check the amount of fuel in the plane. If the result of the action is not visible, how can the error be detected.
Most of the time we are, but when we aren't, our statements can be difficult to justify.
