Following my recent discovery of the field of complex adaptive systems (CAS), I attended a seminar given by Professor Doyne Farmer from the Santa Fe Institute. My goal was to investigate how the theory of these systems relates to, or can be applied to, that of context-aware adaptive systems.
The seminar was a basic discussion about the meaning and the properties of these systems. The goal was to define what exactly is a complex system and what properties do they entail. Some of the properties are as follows:
- Hierarchy
- Distributed Information Processing
- Interacting parts
- Emergent behaviour
- Evolution
- History, lock-in, path dependence
I wish to try to explain each of these properties and possibly relate them to context-aware adaptive systems.
In order to give structure to a CAS, it can be arranged as a hierarchy. The nodes on each level interact with each other and cause emergent nodes on the next level. This is usually as far as we understand or can attempt to model these systems. The nodes on level 2 and so on, however, can also interact with eachother in the same way. Such a system appears to be too complicated for us to comprehend. I intend to read a paper by Herb Simon entitled “The Architecture of Complexity” on this subject.
Distributed Information Processing is another property of CAS. Large tasks are delegated to smaller parts of the system that are specialised in more detailed tasks.
Components of the system may interact with eachother and as a result the emergent behaviour is not obvious from the parts alone.
Complex systems evolve over time according to a number of factors such as price of a product for example. If a price rises, more products are produced, and so on.
History plays an important part in CAS. The behaviour does not only depend on the state that the system is in, it also depends on the means by which that state was reached. This is known as hysteresis, a subject that I wish to become more familiar with.
Other keywords: Organisation, structure, function, ontogeny
Synomyms: cybernetics, self-organisation, plectics, emergence
