“The design of the door should indicate how to work it without any need for signs, certainly without any need for trial and error.”

Two of the most important characteristics of good design:

  1. Discoverability: is it possible to even figure out what actions are possible and where and how to perform them?
  2. Understanding: what does it all mean? How is the end product supposed to be used?

Covers three major areas of design

  1. Industrial Design: creating/developing concepts and specs that optimize function, value, and appearance of products and systems for the mutual benefit of both user and manufacturer
  2. Interaction Design: enhance people’s understanding of what can be done, what is happening, and what has just occurred
  3. Experience Design: practice of designing products, processes, services, events, and environments with a focus placed on the quality and enjoyment of the total experience

The machine does what it is told, no matter how insensible and illogical. Humans, on the other hand, are imaginative and creative, filled with common sense. Yet, to interact with machines, they require us to be precise and accurate, things we are not very good at.

The problem with the designs of most engineers is that they are too logical. We have to accept human behaviour the way it is, not the way we would wish it to be.


  1. Most failures of human-machine systems are due to poor designs rather than human error itself.
  2. Good design accounts of human limitations.

Relevant for human computer interaction and interaction design