• Design must convey:
  • The essence of a device’s operation
  • The way it works
  • The possible actions that can be taken
  • Through feedback, what it is doing at any particular moment
• Design is an act of communication
  • A deep understanding of the audience is required to communicate efficiently
• When humans lack understanding, they will usually make mistakes
  • The conceptual model of a system helps them to understand how a device works
    • These can be oversimplified, as long as they are adequate for understanding how the system works
    • Allows for different behaviour when interacting with different systems
    • Designers should provide a conceptual model through the appearance of the device; otherwise users will create their own and these are likely to be wrong
      • Natural mapping: locating controls where there is a natural and obvious relationship to what they are controlling
• Feedback is required to ensure that the user knows the machine is working correctly
• When designing a device it can be useful to use constraints
  • Give the user less options to choose from
  • The user will not be able to interact with the device in the wrong way
  • When instructions are required, it is bad design
• Affordances can be used when designing, as the intended audience will likely have knowledge of how something should work already; this can be utilised in the design
  • A door with a handle should be pulled; a door without one must be pushed, etc
• Visibility
  • It is key to design the interaction to be visibly clear before the user attempts it
  • Give the user natural signals to tell them what to do, based on the affordances that they already have
  • Using natural signals is called natural design

Norman, D. (2013). The Design of Everyday Things : Revised and Expanded Edition. New York: Basic Books.