B551 Elements of Artificial Intelligence. Introduction to the Course and AI

Transcription

1 B551 Elements of Artificial Intelligence Introduction to the Course and AI David Leake Indiana University Associate Instructors (Will lead programming component) Nihar Khetan Alex Seewald Eriya Terada Ishtiak Zaman 1

2 Goals of the Course Provide understanding of key big ideas of AI Develop abilities in critically analyzing AI problems (and other problems) Develop skills in devising creative solutions to open-ended problems Develop skills programming AI methods Learn toolkit of methods for your future use (useful whether or not you continue in AI!) What Is AI? What do you think it is/should be? 2

3 In-Class Exercise (not to hand in) Divide into two groups per table Each person should write down his/her one-sentence definition of AI Discuss/compare/contrast as a group. Where do you disagree? What do the differences show? What s key? Each group should pick two of the definitions, representing different perspectives, noting strengths/weaknesses/conflicts. Each table should select a presenter to put all 4 definitions from the table on a ppt page on a laptop plugged into the table s display port. Each presenter will show its table s 4 definitions and comment on strengths/weaknesses/conflicts. Definitions of AI from the Literature Think like humans: The exciting new effort to make computers think machines with minds, in the full and literal sense (Haugeland, 1985). the study of mental faculties through the use of computational models. (Charniak and McDermott, 1985) Think rationally: the study of computations that make it possible to perceive, reason, and act. (Winston, 1993) 3

4 Act like humans: The study of how to make computers do things at which, at the moment, people are better (Rich and Knight, 1991) Act rationally: describing and building intelligent agents that receive percepts from the environment and perform actions. (Russel and Norvig, 2005) minor rewording Anything wrong? Where do these Break Down? Examples? Act like humans: The study of how to make computers do things at which, at the moment, people are better (Rich and Knight, 1991) Act rationally: describing and building intelligent agents that receive percepts from the environment and perform actions. (Russell and Norvig, 2005) minor rewording 4

5 Act like humans: The study of how to make computers do things at which, at the moment, people are better (Rich and Knight, 1991) Was writing T E X AI? Act rationally: describing and building intelligent agents that receive percepts from the environment and perform actions. (Russell and Norvig, 2005) minor rewording Is thermostat design AI? 5

6 What are the Dimensions for Definitions of AI? (Why is this important?) Categories of Definitions of AI (Russell & Norvig) Systems that think like humans. (Cognitive modeling) Systems that act like humans. Systems that think rationally. Systems that act rationally. (Textbook s focus) 6

7 Chris Riesbeck s Definition AI is the search for answers to the eternal question, why are computers so stupid? 1996 What does this mean for an AI research agenda? Riesbeck s Focus AI should focus on what is computer stupidity and how can we get rid of it AI as a repair process Not focus on intelligence Most interesting AI projects, such as robot walking do not require intelligence in the sense of playing great chess 7

8 Not understanding simple sentences in context is stupid. Ergo, natural language understanding research is AI. Not being able to solve equations is not stupid. Ergo, numerical analysis is not AI. Not recognizing your own hand in front of your own face is stupid. Ergo, computer vision research is AI. from What next? The future of CBR in postmodern AI by Chris Riesbeck Approaches to AI Cognitive science approach Study of how humans think Build computer programs or systems to model cognitive processes Search for similarities between what is going on in the model and what happens in the brain Study of the nature of intelligence Technological approach Build systems to solve real world problems 8

9 Potential Impact of AI "If you invent a breakthrough in artificial intelligence, so machines can learn that is worth 10 Microsofts. Bill Gates 2011 Was an AmazingYear for AI Video 9

10 Video Video 10

11 What Are the Ramifications of Self-Driving Cars? Your thoughts? Video How Else Can AI Affect Our Lives? 11

12 How can we judge performance of AI systems and progress of AI? 12

13 Sample criteria for judging AI systems Applications side Can humans interact with the machine more naturally? Can it help humans make decisions and guide the reasoning process? Can it replace a human in a task such as driving a car? Cognitive science side Can the computer now think? (What s wrong with this question?) Evaluating Full Intelligence: The Turing Test Alan Turing 1950 addressed Can machines think? Problem: Not operational/informative Turing replaced question with a test: Can a machine pass this test? becomes the operational replacement 13

14 The Turing Test Played with 2 people and a machine Communication by typing alone An isolated person interrogates the other person and machine over teletype Interrogator tries to figure out which one is the human Computer tries to respond like a human What Would You Say? 14

15 What Does the Turing Test Get Right or Wrong? Too weak? Too Strong? Just right? The Loebner Prize Established in 1990 Annual contest to pass the Turing Test Grand prize for passing - $100,000 Not yet claimed Next competition is Sept 19, 2015, Bletchley Park, UK Alice, a past winner (2000, 2001, 2004), is online, as is Mitsuku, the 2013 winner. 15

16 Can Machines Understand Stories? SAM (1978) could summarize simple stories and answer questions about them. Input: Friday evening a car swerved off Route 69. The vehicle struck a tree. The passenger, a New Jersey man, was killed. David Hall, 27, was pronouced dead at the scene by Dr. Dana Blanchard, medical examiner. Frank Miller, 32, of 592 Foxon Rd., the driver, was taken to Milford Hospital by Flanagan Ambulance. He was treated and released. No charges were made. Patrolman Robert Onofrio investigated the accident. 16

17 English Summary: AN AUTOMOBILE HIT A TREE NEAR HIGHWAY 69 FOUR DAYS AGO. DAVID HALL, AGE 27, RESIDENCE IN NEW JERSEY, THE PASSENGER, DIED. FRANK MILLER, AGE 32, RESIDENCE AT 593 FOXON ROAD IN NEW HAVEN, CONNECTICUT, THE DRIVER, WAS SLIGHTLY INJURED. THE POLICE DEPARTMENT DID NOT FILE CHARGES. Spanish Summary: UN AUTO CHOCO CONTRA UN ARBOL CERCA DE LA CARRETERA 69 EL VIERNES AL ANOCHECER. DAVID HALL, DE 27 ANOS, QUE VIVIA EN NEW JERSEY, EL PASAGERO, SE MURIO. FRANK MILLER, DE 32 ANOS, QUE VIVIA EN 593 CALLE FOXON EN NEW HAVEN, CONNECTICUT, EL CHOFER, QUEDO UN POCO HERIDO. EL DEPARTAMENTO DE POLICA NO ACUSO A NADIE. 17

18 Question-Answering Output Q1: Was anyone killed? A1: YES, DAVID HALL DIED Q2: Was anyone hurt? A2: YES, FRANK MILLER WAS SLIGHTLY INJURED. Q3: Why was Miller hurt? A3: BECAUSE THE AUTOMOBILE HIT THE TREE. Q4: Did Miller go to the hospital? A4: YES, HE WAS IN THE MILFORD HOSPITAL. Q5: How did Miller get to the hospital. A5: THE FLANAGAN AMBULANCE COMPANY TOOK HIM TO THE MILFORD HOSPITAL. Are You Convinced? John Searle 18

19 Searle s Chinese Room The Rule Book (if-then rules) 19

20 Where s the Understanding? 20