The Sciences of the Artificial Herbert A. Simon

1. The Sciences of the ArtificialHerbert A. Simon Prefaces & Chapter 1

2. The Natural • Natural science • Body of knowledge aboutobjects or phenomena inthe world • To make thecomplex simple • “to find pattern hidden in apparentchaos”

3. The World We Live In

4. Describing the World We Live In • The world we live in is filled with physical and conceptual artifacts we have designed to meet specific goals • To understand these artifacts we need a way of describing • The natural laws embodied in the artifacts • The human purpose embodied in the artifacts • Should there be a science of the artificial? • The title of this book indicates Simon’s opinion

5. The Artificial • The word artificial is somewhat of a pejorative • Here we will use the term as neutrally as possible • Many verbs used to describe various forms of creation • Artifice, synthesize, design, compose, … • Descriptive vs. normative analyses • Description: an increase in greenhouse gases causes the average temperature to rise • Normative: policies should reduce the emissions of greenhouse gases

6. First Four Boundaries for Science of the Artificial • Artificial things are synthesized (though not always or usually with full forethought) by human beings. • Artificial things may imitate appearances in natural things while lacking, in one or many respects, the reality of the latter. • Artificial things can be characterized in terms of functions, goals, adaptation. • Artificial things are often discussed, particularly when they are being designed, in terms of imperatives as well as descriptives.

7. Environment as a Mold • Fulfillment of purpose involves • Purpose or goal • Character of the artifact • Environment of performance • Natural science can describe aspects of the artifact and its environment • Whether a clock can keep time and whether a knife can cut depends on the artifact and where it is being applied

8. Artifact as Interface • We can reason about artifacts as an interface between • the inner environment of the artifact and • the outer environment of its application • This can simplify reasoning and enable prediction

9. Functional Explanations • We can predict behavior from knowledge of goals and outer environment with little knowledge of inner workings • Only a few characteristics of outer environment may influence success • E.g., Polar animals are likely to blend into a white background for safety and have hair or fat to regulate body temperature • Descriptions of designs can avoid providing details of either the outer or inner (e.g. patent descriptions)

10. Limits of Adaptation • Designing is more complicated than just creating a specification • Need to show at least one inner system that meets goals • When designs fail we learn more about the relations between the inner and outer environment • “To Engineer is Human”, Petroski

11. Understanding by Simulating • An old question • Can a simulation tellus anything we donot already know? • Relation to computersand programming • People often knowthings but not foreseetheir implications • The Moniac

12. Simulations and Simple Interfaces • Skyhook-skyscraper construction of science • Only possible because each level depends on only a very approximate, simplified, abstracted characterization of the system at the next levels. • Computers enable simulation based on generic functional descriptions • Computer science as an empirical science • Designing reliable systems from unreliable components • Design of time-sharing systems • Sometimes too little is known about task environments and have to just build to evaluate

13. Computers as Symbol Systems • Simon (p. 21) “… if computers are organized somewhat in the image of man …” • Relationship between computer and cognitive science is murky • Symbol systems • Entities act as atomic symbols • Symbol structures are expressions about symbols • Symbols can be used to model world but needs • Means to acquire information from external environment • Means to initiate actions on environment

14. Closing and Prelude for Following Discussions • Hypothesis • “a physical symbol system of the sort I have just described has the necessary and sufficient means for general intelligent action.”