Introduction to AIMeta-IntroWhat are the prerequisites?How do I do well in this course?What are the course logistics?How do we stay awake?Summary Meta-IntroWhat is AI?Found on the Web …Why AI?AI Characterizations#1: Act Like HumansTuring Test#2: Think Like Humans#3: Thinking rationally#4: Acting RationallySlide 17Slide 18Bits of HistorySlide 20Slide 21Slide 22Predictions and Reality … (1/3)Predictions and Reality … (2/3)Predictions and Reality … (3/3)State of the ArtWhy is AI Hard?ElizaColby’s PARRYParry meets Eliza…Slide 31CMSC 421Course overviewLearning Goals for ClassIntroduction to AIIntroduction to AIRussell and Norvig: Chapter 1 CMSC421 – Fall 2006Meta-IntroPersonnel: Myself, two TAs: Galileo Namata and Vivek SehgalAnswers to some important questions:What are the prerequisites for this course?How can I do well in this course?What are the course logistics?How do we stay awake in the late afternoon… ?What will we learn in this class?What are the prerequisites?Assume you know how to program. In addition, you should know:basic algorithms, data structures and computational complexityi.e., searching graphs (DFS, BFS)lists, trees, graphs, etc.Difference between an O(n) and an O(2n) algorithm basic logicTruth table for x OR y, x AND y, x IMPLIES ybasic probabilityP(A v B) = P(A) + P(B) – P(A & B)P(A | B) = P(A & B) / P(B)How do I do well in this course?Attend classParticipate in classDo reading Suggestion: 1) Set aside 20 minutes to skim chapter before lecture. 2) After lecture, go back and read the text in depth. Start written assignments earlyAssignments are not designed to be done the night before they are dueStart programming assignments EARLYDo practice problems to study for examsForm study groups. Working together (not copying) is highly encouraged**** More on this in a few slidesWhat are the course logistics?Web Page:http://www.cs.umd.edu/class/fall2006/cmsc421/Mailing list:http://mailman.cs.umd.edu/mailman/listinfo/cmsc421_2006 Forum:https://forum.cs.umd.edu/forumdisplay.php?f=43How do we stay awake?and learn something, !Course Ettiquette:Arrive to class on time; if you must leave during class, please try to limit the disruption/distractionNo cell phones, no side discussionsNo laptops during lectures Participate, Participate, Participateask questions – if you don’t understand the material, probably there is someone else who does not either!some in class exercisesFeedback:please provide feedbackthere will be several opportunities, but also feel free to just come talk to me!Summary Meta-IntroAnswers to some important questions:What are the prerequisites for this course?How can I do well in this course?What are the course logistics?How do we stay awake in the late afternoon… ?What will we learn in this class?What is AI?What is AI?Class Exercise #0, part A:On the 3x5 card you’ve been given, write down what your definition of AIYou may also want to copy your definition to your notes, because you’ll be turning the card in (anonymously, no worries!)We will collect these definitions in 3 minutes!Found on the Web …Found on the Web …AI is the simulation of intelligent human processesAI is the reproduction of the methods or results of human reasoning or intuitionAI is the study of mental faculties through the use computational methodsUsing computational models to simulate intelligent behaviorMachines to emulate humansIntelligent behaviorHumansComputerWhy AI?Cognitive Science: As a way to understand how natural minds and mental phenomena worke.g., visual perception, memory, learning, language, etc.Philosophy: As a way to explore some basic and interesting (and important) philosophical questionse.g., the mind body problem, what is consciousness, etc.Engineering: To get machines to do a wider variety of useful thingse.g., understand spoken natural language, recognize individual people in visual scenes, find the best travel plan for your vacation, etc.AI CharacterizationsAI Characterizations Discipline that systematizes and automates intellectual tasks to create machines that:Think like humansThink rationallyAct like humans Act rationally#1: Act Like Humans#1: Act Like HumansBehaviorist approachNot interested in how you get results, just the similarity to what human resultsExemplified by the Turing Test (Alan Turing, 1950).Turing TestTuring TestInterrogator interacts with a computer and a person via a teletype. Computer passes the Turing test if interrogator cannot determine which is which.Loebner contest: Modern version of Turing Test, held annually, with a $100,000 prize. http://www.loebner.net/Prizef/loebner-prize.htmlParticipants include a set of humans and a set of computers and a set of judges.Scoring: Rank from least human to most human. Highest median rank wins $2000. If better than a human, win $100,000. (Nobody yet…)#2: Think Like Humans#2: Think Like HumansHow the computer performs functions does matterComparison of the traces of the reasoning stepsCognitive science  testable theories of the workings of the human mind•Exemplified by•General Problem Solver (Newell and Simon)•Neural networks•Reinforcement learning But:• some early research conflated algorithm performance => like human (and vice-versa)• Do we want to duplicate human imperfections?#3: Thinking rationallyExemplified by "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 Direct line through mathematics and philosophy to modern AIProblems: 1. Not easy to translate informal real world problem into formal terms (problem formulation is difficult)2. While may be able to solve the problem in principal (i.e. decidable), in practice, may not get the answer in a reasonable amount of time (computationally intractable)#4: Acting Rationally Rational behavior: do the right thingAlways make the best decision given what is available (knowledge, time, resources)Perfect knowledge, unlimited resources  logical reasoning (#3)Imperfect knowledge, limited resources  (limited) rationality•Connection to economics, operational research, and control theory•But ignores role of consciousness, emotions, fear of dying on intelligenceAI CharacterizationsAI Characterizations Discipline that