1. Diagramming process

Schematization is very often a spontaneous act of immediate use, carried out by people unaware of any schema theory. It appears to be a highly effective way of shaping one's own thoughts and communicating them. But to communicate is to oblige the other person to make the transmitted message his own, by taking it over and recreating it.

We are all producers and consumers of patterns.

Two stages can be distinguished in the schematic representation:

• simplification to distinguish the essential from the accessory;

• the reconstruction of reality by disregarding secondary elements.

The two pitfalls to avoid are over-simplification, which distorts reality, and over-complexity, which renders it unintelligible. The approach must therefore...