Hi everybody! Self organizing systems are a key area of the study of complex systems. They show up in a vast number of different guises.

In this unit, I'm going to take you through some idealized models of self organization in biology, in society, in economics.

And the purpose is to really not only show you how people understand self organization to work but also to understand how complex systems scientists make simplifying assumptions...

to build models to allow us some insight into the underlying mechanisms in theses highly complex self organizing systems.

Let's get started.

What do I mean by self organization? I won't define this rigorously but informally, self organization is the production of highly organized patterns or behaviors...

resulting from localized interactions within the components of the system without any centralized leader or architect...

and in which the components have only limited information about the states of neighboring components.

Thus by "self", I mean the behavior arises only due to interactions within the system.

And by "organization", I mean the appearance of what we would call organized patterns.

More formal definitions of organized patterns could be given. For example, using notions of Shannon information or other information theoretic measures.

But I'm not going to delve into such formal definitions here.

Self organization is interesting because on the face of it, it often seems impossible.

How do these simple ants form a complex, ultra strong bridge using their own bodies without any central control or central architect?

How do fish, capable or only relatively simple behaviors on their own, create such perfect schooling behavior that enhances their ability to defeat predators and catch prey.

Self organization is closely related to the notion of emergence, which is the idea that the complex behaviors we see from the group...

cannot easily be understood by adding up the behaviors of the individual components.

All of the self organizing behaviors we will look at here, have what people have called emergent properties or complex behavior from simple rules.

The are of self organization is a great example where idealized computer models have made a huge difference in our understanding of complex systems.

In the this unit we will look at a few examples of particular self organizing behaviors and of idealized models of these phenomenon.

I'll only be able to scratch the surface here, but I'll put on the course materials page some good references for getting deeper into this really fascinating area.