FOUNDATIONS OF ARTIFICIAL INTELLIGENCE Introduction Chapter 1 916202

FOUNDATIONS OF ARTIFICIAL INTELLIGENCE Introduction: Chapter 1 9/16/202 1 1

What is Artificial Intelligence? Artificial: Intelligence: 9/16/2021 2

Some Definitions (I) The exciting new effort to make computers think … machines with minds, in the full literal sense. Haugeland, 1985 (excited but not really useful) 9/16/202 1 3

Some Definitions (II) The study of mental faculties through the use of computational models. Charniak and Mc. Dermott, 1985 A field of study that seeks to explain and emulate intelligent behavior in terms of computational processes. Schalkoff, 1990 (Applied psychology & philosophy? ) 9/16/202 1 4

Some Definitions (III) The study of how to make computers do things at which, at the moment, people are better. Rich & Knight, 1991 9/16/202 1 5

What is AI? Views of AI fall into four categories: Thinking humanly Acting humanly Thinking rationally Acting rationally The textbook advocates "acting rationally" 9/16/202 1 6

Acting humanly: Turing Test Turing (1950) "Computing machinery and intelligence": "Can machines think? " "Can machines behave intelligently? " Operational test for intelligent behavior: the Imitation Game Predicted that by 2000, a machine might have a 30% chance of fooling a lay person for 5 minutes Anticipated all major arguments against AI in following 50 years Suggested major components of AI: knowledge, reasoning, language understanding, learning 9/16/202 1 7

Thinking rationally: "laws of thought" Aristotle: what are correct arguments/thought processes? Several Greek schools developed various forms of logic: notation and rules of derivation for thoughts; may or may not have proceeded to the idea of mechanization Direct line through mathematics and philosophy to modern AI Problems: 1. Not all intelligent behavior is mediated by logical deliberation 2. What is the purpose of thinking? What thoughts should I have? 9/16/202 1 8

Acting rationally: rational agent Rational behavior: doing the right thing The right thing: that which is expected to maximize goal achievement, given the available information Doesn't necessarily involve thinking – e. g. , blinking reflex – but thinking should be in the service of rational action 9/16/202 1 9

Rational agents An agent is an entity that perceives and act This course is about designing rational agents Abstractly, an agent is a function from percept histories to actions For any given class of environments and tasks, we seek the agent (or class of agents) with the best performance Caveat: computational limitations make perfect rationality unachievable design best program for given machine resources 9/16/202 1 10

AI prehistory Philosophy physical system Logic, methods of reasoning, mind as Mathematics Formal representation and proof algorithms, computation, (un)decidability, (in)tractability, probability Economics utility, decision theory Neuroscience physical substrate for mental activity Psychology phenomena of perception and motor control, experimental techniques Computer engineering building fast computers Linguistics knowledge representation, grammar 9/16/202 1 11

Abridged history of AI 1943 1950 1956 1952— 69 1950 s 1965 1966— 73 1969— 79 1980 -1986 -1987 -1995 -- Mc. Culloch & Pitts: Boolean circuit model of brain Turing's "Computing Machinery and Intelligence" Dartmouth meeting: "Artificial Intelligence" adopted Look, Ma, no hands! Early AI programs, including Samuel's checkers program, Newell & Simon's Logic Theorist, Gelernter's Geometry Engine Robinson's complete algorithm for logical reasoning AI discovers computational complexity Neural network research almost disappears Early development of knowledge-based systems AI becomes an industry Neural networks return to popularity AI becomes a science The emergence of intelligent agents 9/16/202 1 12