Terminology

Activity systems perform behaviors and change state.

State: the current values of an entity’s variable properties.

Process: one or more state changes over time, or the logic that determines which state changes lead to which other state changes.

Deterministic: the quality of a system that means its next state is predictable from its current state and input event.

Stochastic: the quality of a system that means its next or future state is not predictable, and appears random.

Linear change: progress or change over time that is represented in a graph as a straight line (or else a regular shape).

Non-linear change: progress or change over time that is represented in a graph as a curve (or else an irregular shape).

In this and related papers:

· Orderly or deterministic <is contrasted with> random or fuzzy, probabilistic or stochastic.

· Linear change or outcome <is contrasted with> non-linear or chaotic change or outcome.

· Adapting (changing variable values) <is contrasted with> evolving (changing variable types or rules).

Chaos

Most people consider orderliness to be a defining characteristic of a system.

In natural language, order and chaos are usually considered to be opposites.

And so, some systems thinkers use chaotic or non-linear to mean disorderly

Yet a system can be orderly (meaning deterministic) and chaotic at the same time. How come?

In a deterministic system, tiny variations in initial state conditions can lead to huge variations in long-term outcomes.

E.g. a weather system is deterministic in the short term and yet chaotic in the long term

Forrester’s “system dynamics” can be used to model social systems as deterministic machines.

When you run the model, it may reveal the system to behave chaotically in the long term – widely different outcomes following small variations in initial conditions.

Also, a system may appear stochastic or random, because you don’t know its internal state or rules, yet actually be deterministic or orderly.

Chaotic system: a system in which a surprisingly wide variety of outcomes or system states follow (sooner or later) from narrow differences in the initial state of the system.

I suspect there to be a relationship as described in the table below

	Linear outcomes	Chaotic outcomes
Ordered process steps	Possible	Possible
Random process steps	Impossible?	Possible

All free-to-read materials at http://avancier.website are paid for out of income from Avancier’s training courses and methods licences.

If you find the web site helpful, please spread the word and link to avancier.website in whichever social media you use.