In Houghton’s (1989) review of educational paradigms, he highlights the gaining importance of chaos theory. Chaos theory is often characterized by the term non-linear. Chaos theory can be found in many disciplines; in structural engineering, the behaviour of a structure under earthquake loads is often seen in terms of non-linear behaviour. Another characteristic of chaos theory is unpredictability. The implications for educational theory, as Houghton suggests, is that we have a realistic model for what happens in highly interactive systems.