Chapter 1 the psychopathology of everyday things

Note that the title mentions Psychopathology (the study of mental illness), not Psychology.

=> The title can be translated to "The study of mental illness caused by everyday things".

Focus: User frustration with simple objects & the lack of intuitive cues.

• Norman door: A term used to describe doors that are confusing or difficult to use due to poor design.

  • If a door requires a sign to tell you how to open it (Push/Pull), it is a Norman Door.
  • The author (Don Norman) is famous for highlighting this design failure.

• The complexity paradox

  • High-tech vs Low-tech: We expect to fail when operating complex machinery (like a jet cockpit).
  • The frustration: We should not struggle with simple daily objects like light switches, faucets, or doors. When we do, it signals a failure in design, not the user.

• The fundamental design principle

  • Intuition over Instruction: A well-designed object should indicate how it works purely through its visual structure.
  • The goal: A user should never need signs ("Push" / "Pull") or trial-and-error to operate a simple device.

• The "door" dilemma

  Why are they confusing?

  Despite being theoretically simple (only two states: open or shut), doors become complex due to variable mechanics:

  • Directionality: Push vs. Pull? Left vs. Right?
  • Mechanism: Swinging vs. Sliding (and which way?)

• Case Study: The "Trapped" friend

  Scenario: A user enters a post office with double rows of glass swinging doors, gets distracted, shifts position slightly, and suddenly finds themselves unable to exit or proceed.

  • The root cause is mechanics vs visibility: The user was not actually locked in; they were simply fighting physics.

    • The mechanics: A swinging door has a hinged side (supported by a pillar) and an unsupported side. You must push the unsupported side to generate torque and open it. Pushing the hinge creates no movement.
    • The error: After shifting position, the user was unknowingly pushing against the hinged side of every door they tried.

  • The design failure: Aesthetics over Utility

    Why couldn't the user see the hinges?

    • Prioritizing beauty: The designer aimed for a "clean" look-no visible pillars, hardware, or "distracting lines."
    • The cost of style: By hiding the structural elements (hinges/pillars), the designer removed the visual cues (signifiers) needed to operate the door.
    • Irony: The doors were likely considered "stylish" or award-winning, yet they failed their primary function: letting people walk through them.

  • Key observation

    "Attractive doors. Stylish. Probably won a design prize."

    Lesson: When design prioritizes aesthetics to the point of obscuring functionality, it creates "unnecessary trouble" and panic for the user.

Two pillars of good design: discoverability & understanding ​

Core thesis: A product fails if a user cannot figure out what actions are possible (discoverability) or what those actions actually mean (understanding).

• Discoverability: Can the user see what actions are possible? Is it obvious where and how to perform them?
• Understanding: Does the user grasp the context? Do the controls and settings make sense relative to the product's function?

Solving the door problem ​

The "trapped friend" story was a failure of discoverability.

• The fix: Relevant components must be visible to communicate the correct message.
• Natural signals: You don't need to ruin aesthetics with ugly signs. Subtle cues like a vertical plate (indicating where to push) or visible pillars allow the brain to naturally interpret how the object works without needing labels.

The complexity trap & user behavior ​

While manuals are acceptable for complex machinery (like nuclear plants), they should be unnecessary for simple objects.

• The spaceship effect: Simple appliances (stoves, washers) now resemble "Hollywood's idea of a spaceship control room" due to feature creep.
• The user's coping mechanism: When faced with a bewildering array of controls, users stop trying to understand the system. Instead, they memorize one or two fixed settings and ignore the rest.

Case study: the Italian washer-dryer ​

Scenario: A highly educated couple (an engineering psychologist and a physician) own a fancy washer-dryer with complex, multi-symbol controls.

• The husband: Refused to go near the machine.
• The wife: Memorized a single setting and ignored all other features.
• The manual: Equally confusing.
• Conclusion: If the design is so complex that users ignore 90% of it, the "whole purpose of the design is lost."

The complexity of modern devices ​

Premise: Everything artificial is designed-from physical furniture to abstract organizational structures (services, lectures, processes, etc.). The goal is to balance engineering requirements with human needs (usability and enjoyment).

The goal of design ​

It is not enough for a product to simply function. To truly fulfill human needs, the design must balance:

• Requirements: Engineering, manufacturing, and ergonomics.
• Experience: Aesthetics, quality of interaction, and emotional impact.
• Outcome: Products should be understandable, usable, and ideally, delightful

Three areas of design ​

• Industrial design: Optimizing function, value, and appearance for the mutual benefit of user and manufacturer.

• Interaction design: Enhancing how people interact with technology and understand what can be done, what is happening, and what has just occurred.

  -> Rely on principles of psychology, design, art, and emotion.

• Experience design: Focusing on the emotional impact and quality of the total experience (service, event, environment).

The conflict: human nature vs machine logic ​

• The machine: Rigid, precise, follows secret rules, lacks common sense, and has no history.
• The human: Imaginative, creative, reliant on common sense, and generally imprecise.
• The friction: Problems arise when machines require people to be precise and accurate (traits we lack). When users fail to follow "bizarre, secret rules," they are blamed for the error.
• The solution: It is the duty of the machine to understand people, not the other way around.

Why human-machine interaction fails ​

Core thesis: The primary cause of poor design is not technology or cost, but a fundamental lack of understanding regarding how humans actually behave.

The three causes of deficiency ​

• Technology: Limitations in what is currently possible.
• Cost: Self-imposed restrictions to keep prices down.
• The main culprit: A lack of understanding of the design principles necessary for human interaction.

The engineer's fallacy ​

Most design is done by engineers who are experts in technology but novices in psychology.

• The false assumption: Engineers believe that because they are people, they automatically understand people.

  -> Human behavior is amazingly complex, not simple.

• The logic trap: Engineers are trained to value logic above all else.

  • The mistake: Believing that a logical explanation is a sufficient substitute for intuitive design.
  • The symptom: Blaming the user with phrases like, "If only people would read the instructions, everything would be all right.", "What are these people doing?", "Why are they doing that?".

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

Case study: Three Mile Island nuclear accident ​

Context: A nuclear reactor was destroyed, nearly causing a massive radiation release.

• Initial diagnosis: "Human error" (blaming the operators).
• Root cause analysis: The control rooms were so poorly designed that error was inevitable.
• The realization: Even experts make mistakes (turning on the wrong light, the wrong burner).
• Key lesson: Design must assume that people will make errors and protect against them, rather than demanding perfection.

Human-centered design (HCD) ​

The context: despite decades of progress in design education, everyday life still feels like a "never-ending fight against confusion" due to complex dashboards, home automation, and kitchen gadgets.

The race between design and technology ​

• The gap: While design principles have improved, technology changes faster than design can keep up.
• The cycle: New technologies and industries tend to repeat the mistakes of the past. It takes time for new inventions to integrate established principles of good design.

What is HCD? ​

A design philosophy that prioritizes human needs, capabilities, and behaviors above all else.

• The foundation: Good design requires an understanding of both psychology and technology.
• The core mechanism: Communication. The device must clearly indicate what actions are possible and what is happening.

The true test: when things go wrong ​

It is relatively easy to design for a scenario where everything goes according to plan. The real challenge-and necessity-is designing for errors.

• Communication during failure: A good design highlights problems clearly so the user understands the issue.
• The payoff: When a machine guides a user through a problem to a solution, the collaboration feels "wonderful" rather than frustrating.

The process: observation & iteration ​

• Why observe? People are often unaware of their true needs or the difficulties they face. You must observe them rather than just asking them.
• The HCD principle: Avoid specifying the problem rigidly at the start.
• The method: Iterate through repeated approximations and rapid tests, modifying the problem definition as you go.

HCD vs other design fields ​

How does HCD fit with industrial, interaction, or experience design?

• HCD is the philosophy and procedure (deep consideration of human needs).
• Industrial/Interaction/Experience design are the areas of focus.

Fundamental principles of interaction ​

Core philosophy: Great design produces pleasurable experiences. When users understand a product, they feel mastery and pride. When they are confused, they feel frustration. Cognition and emotion are tightly intertwined.

The six principles ​

To create "discoverability" (figuring out how a product works), designers rely on:

1. Affordances
2. Signifiers
3. Constraints
4. Mappings
5. Feedback
6. Conceptual models -> Provides true understanding.

Affordance & Anti-affordance ​

Why can we manage well with objects that are unique to us?

• Affordance is not a property of an object

  • An affordance is not a fixed attribute.
  • It depends on the match between the object's physics and the user's capabilities.

• Affordance is a relationship

  • The presence of an Affordance is determined by:

    • The qualities of the object.
    • The abilities of the agent that is interacting.

  • Example: A chair affords lifting, but only if the user is strong enough.

• Example of Anti-affordance: Glass affords seeing through & support, but not walking through.

• To be effective, Affordance and Anti-affordance must be Discoverable.

• Visibility is critical: Affordances exist even if they are invisible, which is dangerous.

  The glass paradox: Glass affords seeing through (transparency) but blocks physical passage (anti-affordance). Because the anti-affordance is invisible, birds fly into windows and people walk into glass doors.

  -> Some means of signaling the presence is required: A property named Signifier.

Signifier ​

• Originally, Affordance was so widespread that it is misused in situations alien to its original meaning.

• The origin (the UI confusion): The term "affordance" was misused by UI designers to describe "where to click."

  • The correction: A touchscreen affords touching (affordance). A circle on the screen tells you where to touch (signifier).

• Signifier's role is to communication of the purpose, structure and operation of the device to the agent.

• Intentional signifier vs Accidental signifier: Signifiers work regardless of intent.

  • Intentional: A "PUSH" sign on a door.
  • Accidental: A flag placed for patriotism inadvertently signifies wind direction. A bookmark saves your place, but the thickness of the remaining pages accidentally signifies how much "torture" (or joy) is left in the book.

• The hierarchy: For designers, Signifiers are more important than affordances. An Affordance is useless if the user cannot perceive it; the signifier bridges that gap.

Confusing Perceived affordance & External signifier

A door with no signifiers or visible affordances

• Example: A Signifier that is both an Intentional signifier and an Accidental signifier.

  • A bookmark, a deliberately placed signifier of one's place in reading a book.

  • The physical nature of books also makes a bookmark an accidental signifier, for its placement also indicates how much of the book remains.

    -> For electronic books, this is different.

Affordance, perceived affordance and signifier ​

• Affordance: The possibilities in the world for how an Agent can interact with something.

  Some are visible, some are invisible.

• Signifier: Signals - like signs, labels, drawings, arrows and diagrams indicating what is to be acted upon/in which direction to gesture, or other instructions.

  • Some signifiers are simply the Perceived affordances. - The handle of a door or the physical structure of a switch.

  • Some Perceived affordances may not be real.

    -> Misleading signifiers.

    -> Can be accidental or purposeful.

Case study: the rubber pipes ​

Scenario: Vertical pipes block a service road.

• The perception: To a driver, they look like steel. The signifier suggests a blocked road.
• The reality: The pipes were rubber. The affordance allowed cars to drive right through them.
• The lesson: Misleading signifiers can hide actual affordances to control behavior (permitting access only to those who know the secret).

Summary ​

• Affordances: the possible interactions between people and the environment. Some affordances are perceivable, others are not.

• Perceived affordance: 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.

"Whenever you see hand-lettered signs pasted on doors, switches or products, trying to explain how to work them... you are also looking at poor design."

Rule: Good design embeds the instruction into the object itself (via signifiers), making external labels unnecessary.

Affordances and signifiers: A conversation ​

Context: A designer is frustrated that users are failing to discover advanced features (swiping up/down) in a restaurant recommendation app.

Mapping ​

Why mapping matters ​

• When a design uses Spatial correspondence between the layout of controls and the devices being controlled, usage becomes intuitive.

  • The goal: The user should immediately know which switch operates which light without needing labels.
  • The result: Immediate understanding and ease of use.

Vehicle mapping examples ​

Different vehicles use different mappings, but all rely on a compelling Conceptual model to make sense to the user.

Types of "natural" mapping ​

Natural mapping occurs when the design exploits analogies that the brain already understands.

• Spatial analogies: To move an object up, move the control up. To control a specific light in a grid, place the switch in the same position within a grid of switches.

• Biological/Cultural standards:

  • Up = More: We universally associate vertical height with intensity or amount (e.g., a volume slider).

• Gestalt principles:

  • Grouping: Related controls should be grouped together.
  • Proximity: Controls should be located close to the item they control.

The cultural caveat ​

"What is natural for one culture is not necessarily natural for another."

Some mappings feel "natural" only because we have learned them. Designers must be aware that cultural views (such as how we view time) can alter what a user perceives as a natural mapping.

Summary (mapping) ​

A device is easy to use when the set of possible actions is visible, when the controls and displays exploit natural mappings.

Feedback ​

The scenario: Why do people repeatedly push the elevator button or the pedestrian crossing button?> The missing link: They lack feedback-a signal confirming that the system has received their request and is acting on it.

• The human example: Even simple tasks like picking up a glass require a complex feedback loop of vision, touch, and muscle sensors (proprioception). Without it, we would crush the glass or drop it.

The rules of effective feedback ​

1. It must be immediate

• Even a delay of 0.1 seconds can be disconcerting.
• Consequence: If the delay is too long, users give up or repeat the action unnecessarily, wasting resources.

2. It must be informative

• The problem: To save money, companies often use cheap, generic lights or beeps.
• The result: A beep tells you something happened, but not what.
• Cryptic codes: Using a single light to flash complex patterns (e.g., "one long flash, two short") is a failure of design. Users cannot memorize these codes or distinguish which machine is beeping.

Inappropriate feedback ​

• Poor feedback can be worse than no feedback at all:

  • Distracting.
  • Uninformative.
  • Irritating.
  • Anxiety-provoking.

• Too much feedback is worse 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 electricity).

• Inappropriate, uninterpretable feedback.

  Just like a backseat driver who won't stop commenting, a machine that beeps, flashes, and talks continuously becomes an irritation.

  • The danger: If a system cries wolf too often (e.g., a dishwasher beeping at 3 a.m.), users will ignore or disable all alerts.
  • The risk: In critical environments (cockpits, nuclear plants, operating rooms), excessive feedback creates a "cacophony" of alarms. This noise interferes with concentration, forcing workers to spend valuable time silencing alarms rather than solving the emergency.

Key observation ​

Feedback must be planned and prioritized.

• Unimportant info: Should be unobtrusive.
• Important signals: Must capture attention.
• Emergency states: Must be coordinated to avoid sensory overload.

Conceptual model ​

• Example: The concept of file and folder.

  • There are no folders & folders in computer.

  • But these are just effective conceptualizations designed to make them easier to use.

  • Some files may be hosted on the cloud.

    -> If the network 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.

• Example of multiple Conceptual models for the same product.

  People's conceptual models for the way that regenerative braking in a hybrid or electrically powered automobile works are quite different for:

  • Average drivers.
  • Technically sophisticated drivers.
  • Whoever must service the system.
  • The system design.

• Conceptual models can be constructed by:

  • Passed on from person to person.
  • Experience.
  • Manual.

• Users can infer these models from the device's structure (affordances, signifiers) or learn them from other people/manuals.

• The conflict: Different users (novice vs expert) may have different models for the same device. A user might even hold conflicting models simultaneously.

• The danger: Simplified models work fine until the underlying assumptions break.

  • Example: A "cloud" file looks like it is on your computer (conceptual model), but if the internet cuts out, you can't save it. The simple model fails to explain why.

Case study: scissors vs. digital watch ​

The refrigerator problem ​

Scenario: A standard refrigerator with two controls: "Freezer" and "Refrigerator".> The user's goal: Adjust the temperature of the freezer.

The false model (What the user thinks)

• Two independent controls for two independent compartments.
• Result: The user tries to adjust one, but unknowingly affects the other.

The real model (How it actually works)

• There is only one cooling unit and thermostat.
• Control A adjusts the thermostat (total coldness).
• Control B adjusts the valve (ratio of cold air sent to each side).
• Result: The controls are highly interactive. Changing one changes everything.

The failure:

• The manufacturer provided controls that suggest a simple (but wrong) model.
• Lack of feedback: Users must wait 24 hours to see if their adjustment worked.
• Conclusion: Even knowing the correct model, the design makes it impossible to know which knob does what without a "laboratory notebook".

The solution ​

• Expensive fix: Independent cooling units for each compartment.
• Smart fix: Use a computer chip to translate the user's intent (two simple knobs) into the complex machine logic (valve/thermostat control), hiding the complexity from the user.

The system image ​

The challenge: The designer knows how the product works, and the user needs to know how it works. However, they cannot talk to each other.

• A System image includes:

  • The physical device itself (appearance, structure).
  • Documentation and manuals.
  • Signifiers and labels.
  • External information (sales literature, websites, past experiences).

The triangle of communication ​

1. The designer: Has the correct Conceptual model (Vertex 1).
2. The product: Isolated from the designer (Vertex 2).
3. The user: Forms their own model based solely on interacting with the product (Vertex 3).

• The disconnect: The designer expects the user's model to be identical to their own.

• The reality: Because the designer is not there to explain things, the entire burden of communication rests on the System image.

• The consequence:

  • If the System image is coherent, the user forms a good model and can recover when things go wrong.
  • If the System image is contradictory (like the refrigerator example), the user struggles and creates a false mental model.

Key takeaway ​

"No matter how brilliant the product, if people cannot use it, it will receive poor reviews."

Good Conceptual models are the key to understandable products, and the System image is the only way to transmit that model to the user.

Here is the summary of the final section, formatted for Notion with sentence case headings.

The paradox of technology ​

The central conflict: Technology offers the potential to make life easier and more enjoyable, yet the added complexities increase difficulty and frustration.

Case study: the evolution of the wristwatch ​

The wristwatch illustrates how technological advancement creates design problems.

The design dilemma ​

1. The problem of physical space

• As devices become "platforms" for multiple activities, they run out of room for physical controls and signifiers.
• Current workaround: Many people abandon watches entirely and use cell phones, which perform the functions better.

2. The future interface

• Convergence: Phones, watches, and computers may merge into wearable units (wrist or head-mounted) with flexible displays or projectors.
• The risk: Without screens or buttons, we may rely on exotic gestures or spoken commands. The challenge becomes: How will we learn and remember them?

The solution: standardization ​

The best way to mitigate this complexity is to establish agreed-upon standards.

• If controls are standardized, we only need to learn them once.
• Challenge: Agreeing on standards is a complex process hindered by competing corporate forces.

Key observation (standardization) ​

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

The design challenge ​

The reality: Great design requires more than great designers; it requires great management. The hardest part of product creation is coordinating the "staggering" number of separate disciplines involved.

The conflict of disciplines ​

Each department views the product through a different lens, often believing their contribution is the most important.

• Marketing: Prioritizes price and features.
• Engineering: Prioritizes reliability.
• Manufacturing: Prioritizes compatibility with existing plants.
• Support: Prioritizes reducing service calls.
• The paradox: "Who is right? Everyone is right." A successful product must satisfy all these competing constraints simultaneously.

Contextual needs ​

The perception of a product changes depending on where the user is interacting with it.

• In the store: The purchaser focuses on price, appearance, and prestige.
• At home: The focus shifts to functionality and usability.
• In the shop: The repair service cares about maintainability (ease of diagnosis and disassembly).

The solution: cross-functional collaboration ​

Major clashes and deficiencies occur when these disciplines operate independently (in silos).

• The fix: Design teams must have representatives from all constituencies present at the same time.
• The goal: To navigate these conflicts using human-centered design, ensuring the product is profitable, functional, and delightful.