Model

<-> Physical Object

A model is an artificially constructed object that makes the observation of another [physical] object easier - M. Mantyla

A collection of graphic tokens, such as points, lines and polygons, forming a 2D or 3D arrangement

Elements

• Tokens
  points, lines, polygons, ...
• Operations
  for the creation and manipulation (arranging) of these tokens

Design World

<-> Physical World

• Defined by the vocabulary of tokens and operations
• Dependent on the design media and instruments
  ex.: drawing board, cardboard models, clay, computer software