Models facilitate understanding users, analyzing complex systems, and describing effective designs. The use of three models contributes to the design of easy-to-use computer systems: the user's conceptual model, the designer's model, and the programmer's model. Here we provide an understanding of the three models, including how they are used and the relationships between them.
Introduction How the use of models facilitates designing for ease of use.
User Understanding the user's perspective - the user's conceptual model.
Designer Specifying what we want the user experience to be - the designer's model.
Implementor Conveying a complete and unambiguous design to the implementors - the implementor's model.