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Design of Everyday Things

Design of everyday things

  • 2 most important characteristics of good design:
    • Discoverability: What actions are possible?
    • Understandability: How is the product supposed to be used?
  • Human Psychology
    • Thinking logically: Engineers are tend to think logically, so they assume everyone thinks like that
    • A lot of human behaviour is unconscious, therefore a lot of our beliefs about how people behave including ourselves are wrong
    • Positive emotionL Ideal for creative thought, but is not very well suited for getting things done
    • Failure should be replaced with learning experience
    • If everything works perfectly, little is learned. Learning occurs when there are difficulties
  • Design Psychology
    • There needs to be collaboration between person and device.
      • If something goes wrong, the device should help person to solve the issue
    • It is the role of the designer to ensure the behavior of machines is understandable to the people who interact with them
    • Take help from external knowledge which is already present in the world
    • Don’t count on much being retained in short term memory
    • Controls should be activity-centric instead of device-centric when spatial mapping is not possible Mapping
      • eg: All switches in auditoriums can be clubbed together based on activity it performs (lecture, computer room etc.) instead of device-oriented (fans, lights, etc.)
    • Best way to design for everyone: Flexibility
  • Fundamental principles of design
    • Affordances
      • Relationship b/w the properties of an object and the capabilities of the agent
      • Determines what action are possible
      • Eg: Chair affords sitting
      • Potential actions that are possible
    • Signifiers
      • Communicates where the action should take place
      • Can use sounds as a signifier
    • Mapping
      • Exploit natural mapping
      • eg: Switches in a room
    • Feedback
      • Must be immediate and informative
      • Should not get in the way
      • Should not be too much or too little
    • Discoverability
      What is possible?
    • Conceptual models
      • They do not have to be accurate as long as they lead to the correct behaviour in the desired situation
    • Constraints
      • Physical, cultural, semantic and logical
      • Interlock
        Operation must take place in proper sequence
      • Lock in
        Preventing from pre maturely stopping
      • Lockout
        Prevents from entering a space
  • How people do things?
    • Gulf of execution: Figure out how the product works
      • Bridge through Signifiers, constraints, Mapping
    • Gulf of evaluation: Figure out what happened
      • Bridge through Feedback and conceptual models
    • Designer should bridge this gap
    • ![[Assets/download.png]]
    • ![[Assets/download (1).png]]
  • 3 levels of processing
    • Visceral
      • Fast and completely subconscious
      • Sensitive to current state of things
    • Behavioural
      • Action is associated with expectation
      • This is the level where it leads to frustration/anger or happiness
    • Reflective
      • Conscious cognition, deep understanding develops
      • Reasoning and decision making
  • Knowledge of: Declarative knowledge
    • facts and rules
    • use rules of discrimination: coins have different sizes
  • Knowledge how: Procedural knowledge
    • Learned by practice and taught by demonstration
  • Types of errors
    • Slips
      • Person intends to do something but ends up doing something else
      • Action performed is not the same as action intended
      • Types: Action based slip or memory lapse slip
      • Slips can occur because of distraction or that the action performed is already very well learned that it can be done without conscious attention
    • Mistakes
      • Wrong goal is established or the wrong plans are followed
      • Types: Rule based, Knowledge based, Memory lapse
      • Cause: Sequence of action interrupted
      • How to combat?
        • Minimize the number of steps
        • Provide vivid reminders of steps needed
  • How to avoid erros?
    • Reward safety, put it above economic pressures
    • Add constraints to block errors
    • Undo
    • Confirmation and error messages
    • Put the knowledge required to operate the technology in the world
    • Use the power of Constraints
  • Our technologies may change, but fundamental principles of interaction are permanent