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The Design of Everyday Things
https://en.wikipedia.org/wiki/The_Design_of_Everyday_Things
Chapter One: The Psychopathology of Everyday Things
Well-designed things do not need explanatory signage or trial-and-error.
Two important characteristics of design:
- Can the user discover what action are possible and how to do them?
- Can the user grok the meaning of the actions and the purpose of the thing?
Designers must design for humans, who are not perfectly logical creatures.
Discoverability is done with
- Affordances
- Signifiers
- Constraints
- Mappings
- Feedback
Understanding comes in the form of a conceptual model of the thing.
Affordances (and non-affordances) are the ways in which a user can (and can't) interact with a thing. The set of interactions is a function of both the thing and the user, so different users will have different affordance with the same thing.
Signifiers tell user how to interact with a thing. They aren't necessarily intentional. Signifiers are defined by effect, not intent. Perceived affordances can act as signifiers.
Mappings are the relationships between controls and their effects. Natural mappings exploit mappings we use naturally, such as spatial mapping and natural expressions of concepts (e.g. intensity).
Feedback tell the user that the system is working; and it must be immediate and clear.
Chapter Two: The Psychology of Everyday Actions
Things present two challenges to people:
- Figure out how thing works and what the user can do to the thing.
- Figure out what thing has done and whether it's what the user wanted.
People often blame themselves instead of the thing when they fail to bridge these gulfs.
Problem 1 is eased by the designer's use of signifiers, constraints, mappings, and by the user's conceptual model.
Problem 2 is eased by feedback and still the user's conceptual model.
Actions occur in seven stages;
- Form a goal.
- Plan an action that accomplishes the goal.
- Specify the sequence of steps in the action.
- Perform the action.
- Perceive the state of the world (the outcome)
- Interpret these perceptions.
- Compare the actual outcome to the goal.
It is useful to understand the root cause of the user's goals, because this ultimately determines which actions they need to take.
Small innovations arise by finding new ways to help users perform actions or achieve specific goals.
Radical innovations find new ways to help users address the root cause of their problem/need.
Cognition makes sense of the world, but emotions assign value.
People depend on their emotions in order to make choices.
Positive emotional states foster creativitiy and lateral thinking. but this lacks direction.
Negative emotional status force focus and can be useful for productivity.
All emotional states causes bias.
Simplified model of the mind, with 3 levels:
- The visceral level governs instantaneous reactions to stimuli. Our visceral reactions are reflexive, and are either instinctive or conditioned over our lifetime. Visceral responses are precursors to emotions. Designers trigger visceral responses by aesthetics.
- The behavioural level governs learned, trained automatic responses, including emotional responses. Designers must understand what users' expectations are and deliver feedback that matches these expectations. Even negative feedback is better than no feedback at all. Changes in a thing's state are relative, so even a change from "completely fucked" to "warning" is emotionally positive, and vice versa for good states.
- The reflective level governs conscious, post-facto analysis and decision-making, blaming, and crediting. This process can alse trigger more powerful, secondary emotions. This is also where the user develops their conceptual model of the thing. This is where memories of a thing are formed and where emotions are attached to a thing and its use.
Designers exploit postive reactions to beautiful things to create a good feeling about the thing.
Merketers sometimes rely on emotions attached to a brand to support an otherwise mediocre product.
The user's conceptual model usually takes the form of a collection of stories, which in turn are causal chains the user believes to exist. If there is a lack of feedback or signifiers on the thing then the user will use their imagination and their experience using other things.
When we are unable to use a thing, we are apt to blame ourselves.
People can learn helplessness: the belief that the user has only their own lack of ability to blame for their failure to use a thing, so they stop trying. Bad design fosters it; good design overcomes it.
Designers should not blame users when they fail to use the thing properly.
User problems are design problems.
Feedback shouldn't indicate failure; it should provide help, especially direct routes to solutions.
Errors should have a minimal cost. Invalid input and other errors shoudl be caught by a safegaurd where possible.
"Error" is like "issue": avoid using this word when something more explanatory can be used, such as "poor communication".
Rather than expecting users to adapt their behaviour to the thing's interface, the thing should be designed for human behaviour as it already is.
Seven fundamental principles of design:
- Discoverability: what actions are possible? What is the current state of the thing?
- Feedback: What are the result of actions? How has the state changed?
- Conceptual model: The user's mental model of how they imagine the thing works. It doesn't need to be correct; it just needs to facilitate usage.
- Affordances: The thing needs to do what the user wants to do.
- Signifiers: For discoverability and feedback.
- Mappings: Intuitive relationships between controls and actions.
- Constraints: Guidance to prevent users from getting into problems.
Don't criticise design unless you can do better.
Chapter Three: Knowledge in the Head and in the World
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Chapter Four: Knowing what to do: Constraints, Discoverability and Feedback
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Chapter Five: Human Error? No, Bad Design
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Chapter Six: Design Thinking
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Chapter Seven: Design in the World of Business
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