Only the geography and anatomy of the subject is described and analyzed; a kind of system of static relations [Most architecture and graphic design systems are of this type.]

Machines that are determined

The level of control in mechanical and cybernetical [sic] systems

As an open and self-maintaining system, having a through-put that transforms unpredicted inputs into outputs [what Maturana, Varela, and Uribe later called an “autopoetic” system]

Of plants and accumulated cells

Specialized receptors, a nervous system, and an “image”

All of the previous six—plus self-consciousness. The system knows that it knows, and knows that it dies

The unit at this level is a role, rather than a state; messages with content and meaning exist, and value systems are developed

The “ultimates” and “absolutes” and the “inescapables” with systematic structure

— Kenneth Boulding, as summarized by Horst Rittel [ 13]

[ 10] has referred to a “moral compass” or scale for interactivity “Reactive > Automatic > Interactive > Instrument > Platform.” Cornock and Edmonds have proposed five distinctions: (i) Static system, (ii) Dynamic-passive system, (iii) Dynamic-interactive system, (iv) Dynamic-interactive system (varying), and (v) Matrix [ 11]. Kenneth Boulding distinguishes nine types of systems [ 12].

System Combinations

One way to characterize types of interactions is by looking at ways in which systems can be coupled together to interact. For example, we might characterize interaction between a person and a steam engine as a learning system coupled to a self-regulating system. How should we characterize computer-human interaction? A person is certainly a learning system, but what is a computer? Is it a simple linear process? A self-regulating system? Or could it perhaps also be a learning system?

Working out all the interactions implied by combining the many types of systems in Boulding’s model is beyond the scope of this paper. But we might work out the combinations afforded by a more modest list of dynamic systems: linear systems (0 order), self-regulating systems (first order), and learning systems (second order). They can be combined in six pairs: 0-0, 0-1, 0-2, 1-1, 1-2, 2-2.

a sense, the two linear systems function as one.

This type of interaction is limited. We might call it pushing, poking, signaling, transferring, or reacting. Gordon Pask called this “it-referenced” interaction, because the controlling system treats the other like an “it”—the system receiving the poke cannot prevent the poke in the first place [ 14].

A special case of 0-0 has the output of the second (or third or more) systems fed back as input to the first system. Such a loop might form a self-regulating system.

[ 11] Cornock, S. and E. Edmonds. “The Creative Process where the Artist is Amplified or Superseded by the Computer.” Leonardo 6 (1973): 11-16.

0-1 Regulating

The output of a linear system provides input for a self-regulating system. Input may be characterized as a disturbance, goal, or energy.

Input as “disturbance” is the main case. The linear

system disturbs the relation the self-regulating system was set up to maintain with its environment. The self-regulating system acts to counter disturbances. In the case of the steam engine, a disturbance might be increased resistance to turning the wheel, as when a train goes up a hill.

Input as “goal” occurs less often. A linear system sets the goal of a self-regulating system. In this case, the linear system may be seen as part of the self-regulating system—a sort of dial. (Later we will discuss the system that turns the dial. See 1-2 below.)

Input as “energy” is another case, mentioned for completeness, though a different type than the previous two. A linear system fuels the processes at work in the self-regulating system; for example, electric current provides energy for a heater. Here, too, the linear system may be seen as part of the self-regulating system.

[ 12] Boulding, K. “General Systems Theory: The Skeleton of Science.” Management Science 2, no. 3 (1956).

[ 13] Rittel, H. “The Universe of Design.” A series of lectures given at UC Berkeley, 1965.

0-0 Reacting

The output of one linear system provides input for another, e.g., a sensor signals a motor, which opens a supermarket door. Action causes reaction. The first system pushes the second.

The second system has no choice in its response. In

[ 14] Pask, G. Conversation Theory: Applications in Education and Epistemology. Amsterdam: Elsevier,1976. (See also an explication of the model in the text at http://pangaro.com/ L1L0/)