This is the third and final post in a sequence on control theory. In the first post I introduced the subject of control theory and stepped through some basics. In the second post I outlined Powers's model, as presented in Behavior: The Control of Perception. This post is a collection of comments on the subject that are only somewhat related, and so I'll use section headings to separate them. I'll also explicitly note the absence of a section on the design of control systems, which is where most of the effort used in talking about them in industrial settings goes, and is probably relevant to philosophical discussions surrounding them.

This is the second of three posts dealing with control theory and Behavior: The Control of Perception by William Powers. The previous post gave an introduction to control theory, in the hopes that a shared language will help communicate the models the book is discussing. This post discusses the model introduced in the book. The next post will provide commentary on the model and what I see as its implications, for both LW and AI.

Behavior: The Control of Perception by William Powers applies control theory to psychology to develop a model of human intelligence that seems relevant to two of LW's primary interests: effective living for humans and value-preserving designs for artificial intelligence. It's been discussed on LW previously here, here, and here, as well as mentioned in Yvain's roundup of 5 years (and a week) of LW. I've found previous discussions unpersuasive for two reasons: first, they typically only have a short introduction to control theory and the mechanics of control systems, making it not quite obvious what specific modeling techniques they have in mind, and second, they often fail to communicate the differences between this model and competing models of intelligence. Even if you're not interested in its application to psychology, control theory is a widely applicable mathematical toolkit whose basics are simple and well worth knowing.

Because of the length of the material, I'll split it into three posts. In this post, I'll first give an introduction to that subject that's hopefully broadly accessible. The next post will explain the model Powers introduces in his book. In the last post, I'll provide commentary on the model and what I see as its implications, for both LW and AI.