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We use models to think about everything.

DRAFT These rough notes need to be sorted out and expanded.

Note: Philosophically, entities like tasks do not exist in the physical world, so they are mental models of how humans understand the universe. However, these models are considered involuntary and unconscious - we use them naturally; it seems unlikely that we can change so fundamental a feature of human cognition to the benefit of design anytime soon. So we limit our discussion to conscious models that we can rationalize about.

A model is:

  • an imperfect or incomplete representation of a thing,
  • meant to capture accurately only certain features of the thing that are pertinent to some discussion or goal.

If a model of something were perfect, it would be indistinguishable from the thing itself. So every model is imperfect.

But that's okay. We use models to capture only those elements of a thing that are interesting to us for some reason.

  • When calculating the distance an object travels, we only worry about it's direction, speed, and acceleration.
  • When calculating whether a part will break, we only need to know its size, shape, and certain physical properties.
  • When planning a trip to Europe, we don't worry about the pilot of the aircraft, or what kind of foam is in the seats. We only want to know the cost and the departure and arrival times of the flight.

Models can be formal, informal, or somewhere in between.

  • Formal models are harder to construct but are more powerful tools.
    • In some cases, one can prove that it is impossible to construct a complete or valid formal model of a thing1).
  • Informal models are not as reliable as formal ones, but they are much easier to build and, in some cases, much easier to use.

A design is a just a model of the thing you're designing. It won't be perfect. But it can be good enough to let a manufacturer create or implement the product.

This raises the question: how much information must the design contain so that it can be made?

  • The answer is as little as possible.
  • The more complicated your design (model) is, the more likely it is to have errors.
  • Also, you don't want to waste time, money, and resources adding detail that isn't needed.

The design process described in this site is designed2) to help make sure your designs have only the necessary information and nothing more.


  • TODO Brief summary of what the concept represents.


  • TODO Motivation for use.
  • TODO Purpose of concept/method.


  • TODO Domain of problems that succumb.
  • TODO Describe unbalanced forces that can be addressed.
  • TODO Inputs: what's needed to generate concept / execute method.
  • TODO Examples of typical situations.


  • TODO Generative description of how to instance the concept or perform the method.
  • TODO Describe resolution /deliverables.


TODO Describe consequences and counter-indications.

yes, even design processes are designed!
design/model.txt · Last modified: 2020.03.12 13:30 (external edit)