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The Design of Everyday Things

This is my summary and notes from The Design of Everyday Things by Don Norman. Please use the link if you decide to buy the book after reading this as it contains my affiliate code. Thanks.

  1. Good design is harder to notice than poor design, partly because good designs fit our needs so well that the design is invisible, serving us without drawing attention to itself.
  2. Bad design screams out its inadequacies, making itself very noticeable.

Chapter 1: The psychopathology of everyday things

  1. Two of the most important characteristics of good design are:
  2. The major areas of design relevant to this book are:
  3. Design is concerned with how things work, how they are controlled, and the nature of the interaction between people and technology.
  4. Engineers are experts in technology & are trained to think logically; However, they are limited in their understanding of people.
  5. Much of a product is designed by engineers; their designs are often too logical because they believe all people must think this way.

We have to accept human behavior the way it is, not the way we would wish it to be.

Human-centered design (HCD)

  1. Human-centered design is a design philosophy — it starts with a good understanding of people and the needs that the design is intended to meet.
  2. This understanding comes primarily through observation — people are often unaware of their true needs or the difficulties they encounter.
  3. HCD principle is to avoid specifying the problem as long as possible but instead to iterate upon repeated approximations.
  4. This is done through rapid tests of ideas, and after each test modifying the approach and the problem definition.

Fundamental principles of interaction

  1. Great designers produce pleasurable experiences.
  2. Discoverability results from the appropriate application of six fundamental psychological concepts:

Affordances

  1. An affordance is a relationship between the properties of an object and the capabilities of an interacting agent (like a human or robot) that determine how the object could possibly be used.
  2. Examples:
  3. The presence of an affordance is jointly determined by the qualities of the object and the abilities of the agent that is interacting.
  4. Anti-affordance is the prevention of interaction.
  5. Affordances exist even if they are not visible. For designers, their visibility is critical — visible affordances provide strong clues to the operations of things:
  6. Perceived affordances help people figure out what actions are possible without the need for labels or instructions.

Signifiers

  1. Affordances are the possible interactions/actions between an interacting agent (like humans) and an object.
  2. Some affordances are perceivable, others are invisible.
  3. Signifiers communicate what actions are possible and where the action should take place (i.e: how it should be done).
  4. Signifiers are any perceivable indicator (signals like signs, labels, drawings, audio, etc) that communicates appropriate behavior to a person.
  5. Some signifiers are perceived affordances, such as the handle of a door or the physical structure of a switch.
  6. Perceived affordances can be ambiguous.
  7. The holes in a scissor are both:
  8. Example:

Mapping

  1. Mapping is a technical term, borrowed from mathematics, meaning the relationship between the elements of two sets of things.
  2. Mapping is an important concept in the design and layout of controls and displays. When the mapping uses spatial correspondence between the layout of the controls and the devices being controlled, it is easy to determine how to use them. E.g:
  3. Vertical position is appropriate for representing intensity or amount: people associate moving the hand up with more, and moving it down with less.
  4. Groupings and proximity are important principles from Gestalt psychology that can be used to map controls to function:

Feedback

  1. Feedback is communicating the results of an action.
  2. Feedback must be:
  3. Poor feedback can be worse than no feedback because it’s:
  4. Too much feedback can be more annoying than too little — it leads people to ignore them all or disable them if possible — which is dangerous because critical feedback is missed.
  5. All action must be confirmed, but feedback needs to be prioritized:

Conceptual models

  1. 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.
  2. Simplified models are valuable only as long as the assumptions that support them hold true.
  3. The conceptual models concerned with here are the simple mental models in the minds of the end-users — not the complex ones found in technical manuals or books.
  4. Mental models are the conceptual models in people’s minds that represent their understanding of how things work.
  5. A single person can have multiple models of an item, each dealing with a different aspect of its operation, and some of them being in conflict.
  6. Conceptual models are valuable:
System image
  1. The designer’s conceptual model is the designer’s conception of the look, feel, and operation of a product.
  2. The system image is what can be derived from the physical structure that had been built (including documentation, instructions, signifiers, …). It’s the combined product information available to the user.
  3. The user’s mental model is developed through interaction with the product and its system image.
  4. Designers expect the user’s model to be identical to theirs, but because they can’t communicate directly with the user, the burden of communication is with the system image.
  5. Good conceptual models are the key to understandable & enjoyable products; Good communication is the key to good conceptual models.
The paradox of technology

The paradox of technology and the challenge for a designer:

The same technology that simplified life by providing more functions in each device also complicates life by making the device harder to learn or use.

The design challenge
  1. Design requires the cooperative effort of multiple disciplines — hence, great design requires great designers and great management.
  2. Each discipline has a different perspective on the relative importance of the many factors that make up a product (often biased by the discipline’s distinct contribution):
  3. Every discipline concern is usually right — the successful product tries to address all of them.
  4. The attributes of a product that customers primarily focus on are dynamic:

Notes

  1. The communication in non-happy paths of modern products is often inadequate:

Chapter 2: The psychology of everyday actions

  1. There are two parts to an action:
  2. When people use a thing, they face two gulfs:
  3. The action cycle:
  4. Root cause analysis
  5. Emotion is highly underrated. In fact, the emotional system is a powerful information processing system that works in tandem with cognition. Cognition attempts to make sense of the world: emotion assigns value.
  6. Systems of cognition:
  7. Three levels of processing:
  8. Design must take place at all levels: visceral, behavioral, and reflective.
  9. People are inclined to assign causal relations when two things occur in succession.
  10. Learned helplessness: Situations in which people experience repeated failure at a task. As a result, they determine that the task cannot be done (at least by themselves).
  11. The corresponding questions to ask in the action cycle:
  1. Well-designed products result in users who can answer all of the above questions while they use the product.

Notes

  1. I always thought that turning a thermostat to the highest setting quickly heats up a room. This chapter explained that this is a flawed mental model. TIL.

Chapter 3: Knowledge in the head and in the world

  1. Precise behavior can emerge from imprecise knowledge (in the head) because:
  2. Whenever knowledge needed to do a task is readily available in the world, the need for us to learn it (completely,) diminishes.
  3. Designers can put sufficient perceivable cues (signifiers, physical constraints, and natural mapping) into a product’s design (knowledge in the world) such that good performance is attained even without prior (complete) knowledge of the product.
  4. People function through their use of two kinds of knowledge:
  5. Relying on knowledge in the world to compensate for incomplete knowledge in the head is susceptible to environmental changes that can make the combined knowledge inadequate.
  6. Psychological research suggests that people only maintain partial descriptions of the things to be remembered.
  7. People learn to discriminate among things by looking for distinguishing features. This is historical baggage — people get confused when a new item is introduced that “breaks” the learned distinguishing feature, like introducing a similar-looking coin.
  8. Constraints simplify memory.
  9. Two classes of memory:
  10. The most effective way of helping people remember is to make it unnecessary.
  11. Two categories of how people use their memories and retrieve knowledge:
  12. Conscious thinking takes time and mental resources; Well-learned skills bypass the need for conscious oversight and control.
  13. Experts minimize the need for conscious reasoning.

    It is a profoundly erroneous truism, repeated by all copy-books and by eminent people when they are making speeches, that we should cultivate the habit of thinking of what we are doing. The precise opposite is the case. Civilization advances by extending the number of important operations which we can perform without thinking about them.
    — Alfred North Whitehead, 1911.

  14. Prospective memory: the task of remembering to do some activity at a future time.
  15. Memory for the future: Denotes planning abilities, the ability to imagine future scenarios.
  16. Two aspects to a reminder:
  17. Natural mappings are those where the relationship between the controls and the object to be controlled is obvious.
  18. Three levels of mapping, arranged in decreasing effectiveness as memory aids:
  19. What mapping is natural is largely dictated by culture.

Tradeoffs between knowledge in the world and in the head

Knowledge in the world Knowledge in the head
Information is readily and easily available whenever perceivable. Material in working memory is readily available. Otherwise considerable search and effort may be required.
Interpretation substitutes for learning. How easy it is to interpret knowledge in the world depends upon the skill of the designer. Requires learning, which can be considerable. Learning is made easier if there is meaning or structure to the material or if there is a good conceptual model.
Slowed by the need to find and interpret the knowledge. Can be efficient, especially if so well-learned that it is automated
Ease of use at first encounter is high Ease of use at first encounter is low.
Can be ugly and inelegant, especially if there is a need to maintain a lot of knowledge. This can lead to clutter. Here is where the skills of the graphics and industrial designer play major roles. Nothing needs to be visible, which gives more freedom to the designer. This leads to a cleaner, more pleasing appearance—at the cost of ease of use at first encounter, learning, and remembering.

Notes

  1. The author talked about how many things are just cultural artifacts that can vary from place to place. E.g:
  2. This got me questioning so many things like why was green chosen to mean go?

Chapter 4: Knowing what to do: Constraints, Discoverability, & Feedback

  1. Four kinds of constraints:
  2. The lack of clear communication among the people and organizations constructing parts of a system is perhaps the most common cause of complicated, confusing designs. A usable design starts with careful observations of how the tasks being supported are actually performed, followed by a design process that results in a good fit to the actual ways the tasks get performed. The technical name for this method is task analysis. The name for the entire process is human-centered design (HCD).
  3. Forcing functions:
  4. People invariably object and complain whenever a new approach is introduced into an existing array of products and systems. Conventions are violated: new learning is required.

    The merits of the new system are irrelevant: it is the change that is upsetting.

  5. Consistency in design is virtuous. It means that lessons learned with one system transfer readily to others. On the whole, consistency is to be followed. If a new way of doing things is only slightly better than the old, it is better to be consistent. But if there is to be a change, everybody has to change. Mixed systems are confusing to everyone. When a new way of doing things is vastly superior to another, then the merits of change outweigh the difficulty of change.
  6. Just because something is different does not mean it is bad.
  7. Standardization is indeed the fundamental principle of desperation: when no other solution appears possible, simply design everything the same way, so people only have to learn once.
  8. Standards should represent the psychological conceptual models, not the physical mechanics.
  9. Standards simplify life for everyone, but also tend to hinder future development.
  10. Skeumorphic: incorporating old ideas or paradigms into new technologies (even when they play no functional role). Skeuomorphism is a helpful way to transition from old to new technologies.

Chapter 5: Human error? No, bad design

Error occurs for many reasons. The most common is in the nature of the tasks and procedures that require people to behave in unnatural ways — staying alert for hours at a time, providing precise, accurate control specifications, all the while multitasking, doing several things at once, and subjected to multiple interfering activities. Interruptions are a common reason for errors, not helped by designs and procedures that assume full, dedicated attention yet that does not make it easy to resume operations after an interruption.

  1. 75-95% of industrial accidents are caused by human error.
  2. Root cause analysis: investigate the accident until the single, underlying cause is found.
  3. Most attempts to find the cause of an accident are flawed for 2 reasons:
  4. When root cause analysis discovers a human error in the chain, its work has just begun: now we apply the analysis to understand why the error occurred, and what can be done to prevent it.
  5. Treat all failures in the same way: find the fundamental causes and redesign the system so that these can no longer lead to problems.
  6. Root cause analysis is intended to determine the underlying cause of an incident, not the proximate cause.
  7. The Five Whys: Japanese procedure for getting at root causes (originally developed at Toyota). The goal is to keep moving the inquiry deeper even after a reason has been found: ask why that was the cause.
  8. Deliberate violations: cases where people intentionally violate procedures and regulations. These happen for different reasons:
  9. Although violations are a form of error, these are organizational and societal errors, important but outside the scope of the design of everyday things.
  10. Human error is defined as any deviance from “appropriate” behavior.
  11. Types of errors:
  12. Checklists are powerful tools, proven to increase the accuracy of behavior and reduce error, particularly slips and memory lapses.
  13. It’s bad design to impose a sequential structure to task execution unless the task itself requires it.
  14. Design lessons from the study of errors:

Resilience engineering is a paradigm for safety management that focuses on how to help people cope with complexity under pressure to achieve success. It strongly contrasts with what is typical today — a paradigm of tabulating error as if it were a thing, followed by interventions to reduce this count. A resilient organization treats safety as a core value, not a commodity that can be counted. Indeed, safety shows itself only by the events that do not happen! Rather than view past success as a reason to ramp down investments, such organizations continue to invest in anticipating the changing potential for failure because they appreciate that their knowledge of the gaps is imperfect and that their environment constantly changes. One measure of resilience is therefore the ability to create foresight — to anticipate the changing shape of risk.

Chapter 6: Design thinking

  1. Design thinking is a process that takes the original problem statement as a suggestion, not a final statement. Then it iteratively attempts to determine what basic, fundamental (root) issue needs to be addressed. Once that is determined, a wide range of potential solutions are explored.
  2. The Double-Diamond Model of Design:
  3. The four different activities of Human-Centered Design are iterative — each cycle through the stages makes some progress. These activities are:
  4. Design and marketing research are complementary but focus on different things:
  5. In HCD, iteration is the repetition of the observe-generate-prototype-test cycle with the aim of achieving continual refinement and enhancement.
  6. The hardest part of designing is getting the requirements right, which means ensuring that the right problem is being solved, as well as that the solution is appropriate. Requirements made in the abstract are invariably wrong. Requirements produced by asking people what they need are invariably wrong. Requirements are developed by watching people in their natural environment.
  7. Activity-centered design: Focuses on activities, not the individual person. Let the activities define the product and its structure.
  8. The HCD process describes an ideal. But practice and reality can be messier and more chaotic.

  9. In theory, there is no difference between theory and practice. In practice, there is.

  10. Norman’s Law of product development: “The day a product development process starts, it is behind schedule and above budget.”
  11. The design process must address numerous constraints like:
  12. The best solution to the problem of designing for everyone is flexibility.

Notes

  1. I like the idea that engineers and other members of the development process are also users that designers should consider in the design process. They are users of the output of the design process.

Chapter 7: Design in the world of business

  1. Basic ways by which manufacturers compete:
  2. Two forms of product innovation:
  3. Radical innovation changes lives and industries. Incremental innovation makes things better. We need both.
  4. Radical innovation can get you on a point at some global best possible hill. From there, incremental innovation gets you to the highest point of that hill.
  5. Featuritis: Feature creep. Factors that contribute to feature creep:
  6. New products are invariably more complex, more powerful, and different in size than the first release of a product.
  7. In her book "Different", Harvard professor Youngme Moon argues that it is this attempt to match the competition that causes all products to be the same. When companies try to increase sales by matching every feature of their competitors, they end up hurting themselves. After all, when products from two companies match feature by feature, there is no longer any reason for a customer to prefer one over another
  8. Technology changes rapidly, but people and culture change slowly.

  9. Plus ça change, plus c'est la même chose.
    The more things change, the more they are the same.

  10. Ideas take a long time to traverse the distance from conception to successful product.
  11. Stigler’s law: the names of famous people often get attached to ideas even though they had nothing to do with them.
  12. The world of product design offers many examples of Stigler’s law. Products are thought to be the invention of the company that most successfully capitalized upon the idea, not the company that originated it.