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CMSC 100 Artificial Intelligence: Human vs. Machine. Professor Marie desJardins Thursday, November 8, 2012. Memory is at the Core (Literally). Remember Hal? “Open the pod bay door, Hal.” “My mind is going...” Memory is at the core of our being (and a computer’s)
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CMSC 100Artificial Intelligence: Human vs. Machine Professor Marie desJardinsThursday, November 8, 2012 Artificial Intelligence
Memory is at the Core (Literally) • Remember Hal? • “Open the pod bay door, Hal.” • “My mind is going...” • Memory is at the core of our being (and a computer’s) • ...but our memories look very different! The first magnetic core memory [www.columbia.edu/acis/history] thebrain.mcgill.ca Artificial Intelligence
Overview • What is AI? (and why is it so cool?) • AI: Past and Present • History of AI • AI Today • Computational vs. Biological Memory • The Skeptics Speak Artificial Intelligence
What is AI? Artificial Intelligence
AI: A Vision • Could an intelligent agent living on your home computer manage your email, coordinate your work and social activities, help plan your vacations…… even watch your house while you take those well planned vacations? Artificial Intelligence
Main Goals of AI • Represent and store knowledge • Retrieve and reason about knowledge • Behave intelligently in complex environments • Develop interesting and useful applications • Interact with people, agents, and the environment Artificial Intelligence
Foundations of AI Computer Science & Engineering Mathematics Philosophy AI Economics Biology Psychology Linguistics Cognitive Science Artificial Intelligence
Big Questions • Can machines think? • If so, how? • If not, why not? • What does this say about human beings? • What does this say about the mind? • And if we can make machines think, should we? Artificial Intelligence
History of AI Artificial Intelligence
Timeline • 1950: Alan Turing proposes the Turing test • 1956: Dartmouth conference, “artificial intelligence” coined • 1958: Lisp programming language for symbolic reasoning created • 1965: First expert system (Dendral – chemistry modeling) • 1969: SRI’s Shakey the robot: perception and problem solving • 1971: BKG backgammon program defeats the world champion • 1997: Deep Blue defeats Garry Kasparov, world chess champion • 2007: Checkers is solved (unbeatable program created) • 2012: Watson beats Jeopardy! champions Ken Jennings and Brad Rutter Artificial Intelligence
Early AI: Eliza • ELIZA: A program that simulated a psychotherapist interacting with a patient and successfully passed the Turing Test • Implemented at MIT during 1964-1966 by Joel Weizenbaum • First script was DOCTOR • Simple pattern-matching • Each pattern had an associated reply which might include bits of the input (after simple transformations (my your) • Weizenbaum was shocked at reactions • Psychiatrists thought it had potential • People unequivocally anthropomorphized • Let me tell you my problems... • Many thought it solved the natural language problem!! Artificial Intelligence
Eliza Speaks I am the psychotherapist. Please, describe your problems. i'm having a hard time with my students Why do you say that? well, they keep asking me for money Maybe your plans have something to do with this. what plans? Is it because of your life that you say what plans? No, it's because I didn't know what you were talking about Is it because you didn't know what I was talking about that you came to me? no, it's because i wanted to see if you could pass the turing test Does it bother you that you wanted to see if I could really pass the turing test? ….. How do you reconcile problems at school? T his is a waste of time. Good bye My secretary will send you a bill. Artificial Intelligence
Early AI: Parry • Kenneth Colby modeled a paranoid using the same techniques as Eliza, around 1968 • PARRY has basic emotions. If it gets angry, its replies become more hostile • In a Turing test, expert psychiatrists were unable to distinguish PARRY’s ramblings from those of real paranoids Artificial Intelligence
PARRY Speaks Good afternoon. My name is Doctor Jones. Pleased to meet you. How are you? All right I guess. Could you tell me your name? Pat Smith. I though you might have some problems. I've been upset lately. By what? People get on my nerves sometimes. Tell me more. Do you know anything about bookies? ... Artificial Intelligence
Please tell me *this* isn't AI! P: I don't understand your motives. E: Why don't you understand my motives? P: Shouldn't I be? E: Why do you say that just now? P: That's just the way it is. E: Suppose that's the way it were not. P: So? E: I am not sure I understand you fully. P: You harp on the same questions too much. E: What does that similarity suggest to you? P: I don't get you. E: Do you wish that you did get I? Artificial Intelligence
Turing Test • Three rooms contain a person, a computer, and an interrogator • The interrogator can communicate with the other two by “teleprinter” (or, say, AIM) • The interrogator tries to determine which is the person and which is the machine • The machine tries to fool the interrogator into believing that it is the person • If the machine succeeds, then we conclude that the machine can think Artificial Intelligence
The Loebner Contest • A modern version of the Turing Test, held annually, with a $100,000 cash prize • Hugh Loebner was once director of UMBC’s Academic Computing Services (née UCS, lately OIT) • http://www.loebner.net/Prizef/loebner-prize.html • Participants include humans, computers (chatbots), and judges • Scoring • Rank from least human to most human • Highest median rank wins $2000 • If better than a human, win $100,000 (Nobody yet…) • 2012 winner: Chip Vivant, http://www.chipvivant.com/ Artificial Intelligence
What’s Easy and What’s Hard? • It’s been easier to mechanize many of the high-level tasks we usually associate with “intelligence” in people • e.g., symbolic integration, proving theorems, playing chess, medical diagnosis • It’s been very hard to mechanize tasks that lots of animals can do • walking around without running into things • catching prey and avoiding predators • interpreting complex sensory information (e.g., visual, aural, …) • modeling the internal states of other animals from their behavior • working as a team (e.g., with pack animals) • Is there a fundamental difference between the two categories? Artificial Intelligence
AI Today Artificial Intelligence
Who Does AI? • Academic researchers (perhaps the most Ph.D.-generating area of computer science in recent years) • Some of the top AI schools: CMU, Stanford, Berkeley, MIT, UIUC, UMd, U Alberta, UT Austin, ... (and, of course, UMBC!) • Government and private research labs • NASA, NRL, NIST, IBM, AT&T, SRI, ISI, MERL, ... • Lots of companies! Artificial Intelligence
Computational vs. Biological Memory Artificial Intelligence
How Does It Work? (Humans) • Basic idea: • Chemical traces in the neurons of the brain • Types of memory: • Primary (short-term) • Secondary (long-term) • Factors in memory quality: • Distractions • Emotional cues • Repetition Artificial Intelligence
How Does It Work? (Computers) • Basic idea: • Store information as “bits” using physical processes (stable electronic states, capacitors, magnetic polarity, ...) • One bit = “yes or no” • Types of computer storage: • Primary storage (RAM or just “memory”) • Secondary storage (hard disks) • Tertiary storage (optical jukeboxes) • Off-line storage (flash drives) • Factors in memory quality: • Power source (for RAM) • Avoiding extreme temperatures Speed Size Artificial Intelligence
Measuring Memory • Remember that one yes/no “bit” is the basic unit • Eight (23) bits = one byte • 1,024 (210) bytes = one kilobyte (1K)* • 1,024K (220 bytes) = one megabyte (1M) • 1,024K (230 bytes) = one gigabyte (1G) • 1,024 (240 bytes) = one terabyte (1T) • 1,024 (250 bytes) = one petabyte (1P) • ... 280 bytes = one yottabyte (1Y?) * Note that external storage is usually measured in decimal rather than binary (1000 bytes = 1K, and so on) Artificial Intelligence
Showdown • Computer capacity: • Primary storage: 64GB • Secondary storage: 750GB (~1012) • Tertiary storage: 1PB? (1015) • Computer retrieval speed: • Primary: 10-7 sec. • Secondary: 10-5 sec. • Computing capacity: 1 petaflop (1015 floating-point instructions per second), very special purpose • Digital • Extremely reliable • Not (usually) parallel • Human capacity: • Primary storage: 7 ± 2 “chunks” • Secondary storage: 108432 bits?? (or maybe 109 bits?) • Human retrieval speed: • Primary: 10-2 sec • Secondary: 10-2 sec • Computing capacity: possibly 100 petaflops, very general purpose • Analog • Moderately reliable • Highly parallel Artificial Intelligence
It’s Not Just What You “Know” • Storage • Indexing • Retrieval • Inference • Semantics • Synthesis • ...So far, computers are good at storage, OK at indexing and retrieval, and humans win on pretty much all of the other dimensions • ...but we’re just getting started • Electronic computers were only invented 60 years ago! • Homo sapiens has had a few hundred thousand years to evolve... Artificial Intelligence
The Skeptics Speak Artificial Intelligence
Mind and Consciousness • Many philosophers have wrestled with the question: • Is Artificial Intelligence possible? • John Searle: most famous AI skeptic • Chinese Room argument • Is this really intelligence? ? ! Artificial Intelligence
What Searle Argues • People have beliefs; computers and machines don’t. • People have “intentionality”; computers and machines don’t. • Brains have “causal properties”; computers and machines don’t. • Brains have a particular biological and chemical structure; computers and machines don’t. • (Philosophers sometimes make claims like “People have intentionality” without actually saying what “intentionality” is, except (in effect) “the stuff that people have and computers don’t.”) Artificial Intelligence
Let’s Introspect For a Moment... • Have you ever learned something by rote that you didn’t really understand? • Were you able to get a good grade on an essay where you didn’t really know what you were talking about? • Have you ever convinced somebody you know a lot about something you really don’t? • Are you a Chinese room?? • What does “understanding” really mean? • What is intentionality? Are human beings the only entities that can ever have it? • What is consciousness? Why do we have it and other animals and inanimate objects don’t? (Or do they?) Artificial Intelligence
Just You Wait... Give us another 10 years! or 20... or 30... or 50... Artificial Intelligence