Models

The term `model' is also a term which has many different meanings, from model railway trains through architectural models to Twiggy and Claudia Schiffer. In the context of theories, a model is a representation of a segment of the perceived world, usually in terms of objects, sets, relations and functions, which is described by a theory.

Abstract model:

An abstract model is an algebraic structure defining objects and relations described by a theory.

Empirical model:

An empirical model denotes objects and relations in the perceived world, and is descibed by an empirical theory.

Operational model:

An operational model is a computer programme with data structures which represent objects and relations in the perceived world, and procedures which emulate events in the real world.