The Invisible Computer: Why Good Products Can Failure, the Personal Computer Is So Complex, and Information Appliances Are the Answer, 1998. 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. No part of this book may be reproduced in any form without written permission, except in the case of short quotes included in critical articles and reviews.
Books published by Basic Books are available at special discounts for large purchases in the United States by corporations, institutions, and other organizations. Constraints Imposing Desired Behavior 141 Conventions, Constraints and Benefits 145 Faucet: Design History 150 Using Sound as Markers 155. Double Diamond Design Model 220 Human-Centered Design Process 221 What I Just Told You.
PREFACE TO THE REVISED EDITION
- The Psychopathology of Everyday Things Signifiers are the most important addition to the chapter, a con-
- The Psychology of Everyday Actions The chapter has one major addition to the coverage in the first edi-
- Knowledge in the Head and in the World Aside from improved and updated examples, the most important
- Human Error? No, Bad Design The basics are unchanged, but the chapter itself has been heavily
- Design Thinking This chapter is completely new. I discuss two views of human-
- Design in the World of Business This chapter is also completely new, continuing the theme started
In the twenty-five years since the first edition of the book, technology has undergone a massive change. Although the basic design principles of The Design of Everyday Things are still as true and important as when the first edition was written, the examples were badly out of date. For readers familiar with the previous edition of this book, here is a brief overview of the changes.
For example, the original book says nothing about what has come to be called user experience (a term I was one of the first to use when the group I led at Apple in the early 1990s called itself "the User Experience Architect's Office"). ”). This section examines the way different cultures view time; the discussion may surprise you. I am updating the classification of errors to reflect progress since the publication of the first edition.
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 PSYCHOPATHOLOGY OF EVERYDAY
Why are they doing that?” The problem with most engineers' plans is that they are too logical. But there is a sixth principle, perhaps the most important of all: the conceptual model of the system. When mapping uses a spatial correspondence between the arrangement of controls and the devices you control, it's easy to determine how to use them.
The mapping between holes and fingers - the set of possible operations - is marked and bounded by the holes. Conceptual model A is provided by the image of the refrigeration system as derived from controls. When the system image is incoherent or inappropriate, as in the case of a refrigerator, then the user cannot easily operate the device.
A designer's conceptual model is the designer's conception of the look, feel, and function of a product.
THE PSYCHOLOGY OF EVERYDAY
This felt good to me - the cabinet drawer moved slightly - but it still wouldn't open. This is the planning phase, which determines which of the many possible plans of action should be followed. Once we have determined what actions to take, we must actually take them - the stages of execution.
This is an example of event-driven behavior: a sequence starts with the world, results in state evaluation, and goal formation. 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. For designers, the most critical aspect of the behavioral level is that every action is associated with an expectation. The behavioral level is about expectations, so it is sensitive to the expectations of the action sequence and then the interpretations of the feedback.
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 full and ongoing information about the results of actions and the current state of the product or service.
KNOWLEDGE IN THE
It can be distributed – partly in the head, partly in the world and partly in the world's limitations. Much of the knowledge a person needs to perform a task can be derived from the information in the world. Behavior is determined by combining knowledge in the head with knowledge in the world.
Although it is best if people have significant knowledge and experience in using a particular product (knowledge in the head). Combine the two, knowledge in the head and in the world, and the performance is even better. Signifiers, physical constraints, and natural mappings are all observable signals that function as knowledge in the world.
All that is needed is a combination of knowledge in the world and in the head, which enables unambiguous decisions. 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.
Effective memory uses all available data: knowledge in the world and in the head, combining the world and the mind. Head knowledge is efficient: no search and interpretation of the environment is required. As we just discussed, reminders provide a good example of the relative trade-offs between knowledge in the world versus knowledge in the head.
Learning becomes knowledge in the world depends more easily on whether it makes sense or on the skill of the designer. Natural cartography, a topic from Chapter 1, provides a good example of the power of combining knowledge in the world with knowledge in the head. In the case of stove controls, it is obviously not possible to place the controls directly on the burner.
With a good natural mapping, the relationship between the control and the burner is fully integrated into the world; the load on human memory is greatly reduced.
KNOWING WHAT TO DO: CONSTRAINTS,
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. I can count on the light switches in the room or auditorium to be uncontrollable.
With six light switches mounted in a one-dimensional array, vertically on the wall, there is no way they can naturally map to the two-dimensional, horizontal placement of the lights in the ceiling. Match the layout of the lights to the layout of the switches: the principle of natural mapping. Starting a car has a coercive function associated with it - the driver must have a physical object that gives permission to use the car.
Because the vehicle will not start without the authentication proven by possession of the key, this is a mandatory function. It is the signifier component of perceived affordability that enables people to determine the possible actions. The merits of the new system are irrelevant: it is the change that is disturbing.
To be somewhat fair to the scheme's inventor, it works as long as you always use two hands to adjust both taps at the same time. One way to overcome the fear of the new is to make it look like the old.
HUMAN ERROR?
NO, BAD DESIGN
Root cause analysis is the name of the game: investigate the accident until the single root cause is found. There is still a tendency to stop too soon, perhaps when the limit of the investigator's understanding has been reached. But when the committees were investigating the complex causes of the incidents, why did they stop after finding human error.
The committees never went far enough to find the deeper, root causes of the accidents. But when someone says, "It was my fault, I knew better," this is not a valid analysis of the problem. Failure can be understood through reference to the seven stages of the action cycle in Chapter 2 (Figure 5.2).
Steps occur in the execution of a plan or in the perception or interpretation of the result - the lower stages. Memory lapses can occur at any of the eight transitions between stages, shown by the X's in Figure 5.2B. The study of slips is the study of the psychology of everyday mistakes —. what Freud called "everyday psychopathology".
Capture errors require that some of the action sequences involved in the two activities are identical, with one sequence being far more familiar than the other. All that is needed is a lack of attention to the desired action at the critical junction when the identical parts of the sequences diverge in the two different activities. They can lead to several types of errors: failing to perform all steps of a procedure;.
Among other things, our memories tend to overgeneralize the ordinary and overemphasize the incongruous. If the error occurs during the execution of the rule, it is most likely a slip.
