Chapter Ten Artificial Intelligence I: Definitional Perspective

Historical Perspective  Artificial Intelligence (AI) has been a driving force behind our quest to create a machine in our own image.  Automata begin to appear for general public consumption during the late 19 th century.  The advent of electronic computation has led to an information revolution in the 21 st century characterized by machines that supply expert advice, control the environment, and emulate human thinking.

Philosophical Issues-Man as a Machine  Descartes ( ) raises the mind-body question. In particular, “What is the difference between a person and a machine?” “Treatise on Man” includes a comparison between a human being and a hypothetical “statue or machine” that operates like a clock or hydraulic fountain. Descartes proposes that humans possess a “rational soul” whereas animals are not capable of reasoning (“I think, therefore I am.”)  Humans have had difficulty accepting two important theories: the earth is not the center of the universe and evolution. Is there a third theory that we need to accept— man is a complex machine?

Evaluating Descartes’ Approach Debate over Descartes is religious in nature. The atheist philosophers of the 18 th century took issue with the idea that a “soul” separates us from the machine-like model for other animals. Debate over Descartes is religious in nature. The atheist philosophers of the 18 th century took issue with the idea that a “soul” separates us from the machine-like model for other animals. Descartes' ideas came into direct conflict with the teachings of the religious community of his time. Descartes' ideas came into direct conflict with the teachings of the religious community of his time. Descartes tries to avoid the conflict; his “machine” is not a man, simply a “statue” that God forms with the explicit intention of making it as much as possible like us. Descartes tries to avoid the conflict; his “machine” is not a man, simply a “statue” that God forms with the explicit intention of making it as much as possible like us.

Mechanical Computation  One aspect of an intelligent agent rests on its ability to perform calculations  Mechanical calculators represent automata capable of “imitating” human intelligence on a “primitive” level.  The abacus is developed in 2600 B.C.  In the 19 th century, Charles Babbage develops mechanical machines that anticipate the modern electronic digital computer. They are a forerunner of an ultimate “intelligent agent.”

Defining AI There may not be a single definition. Alternatives serve to support the authors' special interests. There may not be a single definition. Alternatives serve to support the authors' special interests. The cognitive scientific goal of AI is to codify knowledge (and meta-knowledge or “knowledge about knowledge itself”) in order to assemble systems to explain intelligence and consciousness itself. The cognitive scientific goal of AI is to codify knowledge (and meta-knowledge or “knowledge about knowledge itself”) in order to assemble systems to explain intelligence and consciousness itself. The engineering goal of AI is to assemble systems using a computer’s inventory of knowledge and facilities in order to solve real-world problems. The engineering goal of AI is to assemble systems using a computer’s inventory of knowledge and facilities in order to solve real-world problems.

Evaluating the Concept of AI Strong AI: advocates seek to build machines whose total abilities (including intellectual) cannot be distinguished from those of a human being. The optimism of these advocates has gradually given way as they appreciate the extreme challenges to be surmounted. They continue to dream of this ultimate goal. Strong AI: advocates seek to build machines whose total abilities (including intellectual) cannot be distinguished from those of a human being. The optimism of these advocates has gradually given way as they appreciate the extreme challenges to be surmounted. They continue to dream of this ultimate goal. Applied AI: employs advanced information processing and has enjoyed the most success regarding “intelligent” machines. The focus of its advocates is to produce commercially sustainable “smart machines.” Applied AI: employs advanced information processing and has enjoyed the most success regarding “intelligent” machines. The focus of its advocates is to produce commercially sustainable “smart machines.”

Can a Machine Think and Understand? This question may be pointless. Noam Chomsky suggests it is a question of decision, not fact. We must agree on what defines intelligence, thinking, understanding (and ultimately consciousness). This question may be pointless. Noam Chomsky suggests it is a question of decision, not fact. We must agree on what defines intelligence, thinking, understanding (and ultimately consciousness). If a computer passes an “intelligence” test, would we impart intelligence to it? McCarthy and Shannon note that we could “stack the deck”—design a program with preprogrammed responses. If a computer passes an “intelligence” test, would we impart intelligence to it? McCarthy and Shannon note that we could “stack the deck”—design a program with preprogrammed responses. Minsky: “Intelligence” is our name for whichever problem-solving mental processes we do not yet understand. Minsky: “Intelligence” is our name for whichever problem-solving mental processes we do not yet understand.

Learning as an Element of Intelligence Behaviorists identify several forms of learning that should form part of an intelligent agent’s repertoire of capabilities. Behaviorists identify several forms of learning that should form part of an intelligent agent’s repertoire of capabilities. Trial-and-error: try various responses to a stimulus and remember the one that solves the problem. Trial-and-error: try various responses to a stimulus and remember the one that solves the problem. Rote: direct association between a stimulus and a response (memorizing). Rote: direct association between a stimulus and a response (memorizing). Operant conditioning: Using a system of positive and negative reinforcements, gradually develop a response that is appropriate to the stimuli. Operant conditioning: Using a system of positive and negative reinforcements, gradually develop a response that is appropriate to the stimuli.

Reasoning as an Aspect of Intelligence The ability to draw inferences appropriate to the facts and situation. Problem-solving: devise a strategy to complete a task. (Machine) Perception: achieved when the environment is scanned and converted to a set of abstractions (objects, features, relationships). Language understanding may comprise the highest form of intelligence. This remains a daunting achievement for machines because it must involve “linguistic understanding.”

The Central Processing Unit (CPU) The Central Processing Unit (CPU) The Computer as the Tool of AI Research MemoryMemory Input/Output(I/O)Input/Output(I/O) Communication Channel or “Bus” External environments CPU: Executes instructions, controls sequence Memory: Stores instructions, answers I/O: Interacts with external world (e.g., a user) Bus: Communication between parts of the system

Evaluation of the Computer as a Model of Brain Organization The functioning of the body is too complicated to be supported by a single computer (“brain”). The analogy of the brain as the repository of a “CPU” cannot support the processing necessary to maintain homeostasis. The analogy of the brain as the repository of a “CPU” cannot support the processing necessary to maintain homeostasis. The Network Approach considers processing and knowledge representation to be distributed. The Network Approach considers processing and knowledge representation to be distributed.

Programming and Its Limitations Program: a series of instructions that a user devises for the computer to execute. Program: a series of instructions that a user devises for the computer to execute. High Level Language programming: Programs built to understand “English-like” commands. High Level Language programming: Programs built to understand “English-like” commands. The limitations of HLL programs have led to the development of “user-friendly” applications focused on solving problems in AI. The limitations of HLL programs have led to the development of “user-friendly” applications focused on solving problems in AI.

The Turing Test Machine intelligence Human intelligence Interrogator If an interrogator cannot distinguish between machine intelligence and human intelligence then the machine passes the Turing Test (TT) for intelligence.

Evaluation of the TT Theological: Thinking is a function of man’s God-given immortal soul. No animal or machine can think. Theological: Thinking is a function of man’s God-given immortal soul. No animal or machine can think. “Head-in-the-sand” argument: Consequences of thinking machines are too dreadful to contemplate. “Head-in-the-sand” argument: Consequences of thinking machines are too dreadful to contemplate. Mathematical: Some theorems can neither be proved nor disproved. Mathematical: Some theorems can neither be proved nor disproved. Consciousness: No machine can write a sonnet. Consciousness: No machine can write a sonnet. Disabilities: Machines can follow instructions but you cannot instruct them to have a sense of humor. Disabilities: Machines can follow instructions but you cannot instruct them to have a sense of humor. Lady Lovelace argument: A machine can never do anything really new. Lady Lovelace argument: A machine can never do anything really new.

Overall Evaluation of the AI Concept Turing’s predictions have failed to materialize. Turing’s predictions have failed to materialize. Cognitive scientists have an abiding belief that humans cannot, and should not, be viewed merely as machines. Cognitive scientists have an abiding belief that humans cannot, and should not, be viewed merely as machines. The modern computer has the capacity to re-create “human-like” behavior for limited- environment circumstances. The modern computer has the capacity to re-create “human-like” behavior for limited- environment circumstances.