What is AI? Copyright © 2008 by Helene G. Kershner What is AI? AI = Artificial Intelligence Artificial Intelligence (AI) is the area of computer science focusing on creating machines that can engage on behaviors that humans consider intelligent. http://library.thinkquest.org/2705/ Copyright © 2008 by Helene G. Kershner What is AI? Turing Test A machine would be considered intelligent it could not be distinguished from a person during a “blind” comparison test. Turing Test A person (“judge”) would ask questions via a computer terminal of two “entities.” One entity would be a human, the other a machine/computer. “If the judge regularly failed to correctly distinguish the computer from the human, then the computer was said to have passed the test.” © István S. N. Berkeley Ph.D. 1997. “The Turing test is a one-sided test. A machine that passes the test should certainly be considered intelligent, but a machine could still be considered intelligent without knowing enough about humans to imitate a human.” http://www-formal.stanford.edu/jmc/whatisai/node1.html Copyright © 2009 by Helene G. Kershner What is AI? – John McCarthy Computer Scientist & Cognitive Scientist A cognitive scientist studies the nature of intelligence Combines psychology, philosophy, neuroscience, linguistics, anthropology, computer science, sociology and biology http://en.wikipedia.org/wiki/Cognitive_science He coined the word Artificial Intelligence Received the Turing Award in 1971 for his work in AI. Turing award is given by ACM to “an individual selected for contributions of a technical nature made to the computing community. The contributions should be of lasting and major technical importance to the computer field". Often recognized as the “Nobel Prize of computing” http://en.wikipedia.org/wiki/Turing_Award Copyright © 2009 by Helene G. Kershner What is AI? -- John McCarthy What is artificial intelligence? AI “it is the science and engineering of making intelligent machines, especially intelligent computer programs. It is related to the similar task of using computers to understand human intelligence, but AI does not have to confine itself to methods that are biologically observable.“http://www-formal.stanford.edu/jmc/whatisai/node1.html So if it looks like it is intelligent, and acts like it is intelligent even if it does so in ways different from human it could be considered intelligent. Sort of “I’ll know it when I see it.” Copyright © 2009 by Helene G. Kershner What is AI? – John McCarthy Can we even really define intelligence? Intelligence is the “computational part of the ability to achieve goals in the world. Varying kinds and degrees of intelligence occur in people, many animals and some machines.” But what is intelligence really? Is there a definition of intelligence that doesn’t depend on relating it to human intelligence? “ Not yet. The problem is that we cannot yet characterize in general what kinds of computational procedures we want to call intelligent. We understand some of the mechanisms of intelligence and not others.”http://www-formal.stanford.edu/jmc/whatisai/node1.html Copyright © 2009 by Helene G. Kershner What is AI? – John McCarthy “Isn't AI about simulating human intelligence? Sometimes but not always or even usually. On the one hand, we can learn something about how to make machines solve problems by observing other people or just by observing our own methods. On the other hand, most work in AI involves studying the problems the world presents to intelligence rather than studying people or animals. AI researchers are free to use methods that are not observed in people or that involve much more computing than people can do. “ http://www-formal.stanford.edu/jmc/whatisai/node1.html Copyright © 2009 by Helene G. Kershner What is AI? -- John McCarthy “When did AI research start? After WWII, a number of people independently started to work on intelligent machines. The English mathematician Alan Turing may have been the first. He gave a lecture on it in 1947. He also may have been the first to decide that AI was best researched by programming computers rather than by building machines. By the late 1950s, there were many researchers on AI, and most of them were basing their work on programming computers. http://www-formal.stanford.edu/jmc/whatisai/node1.html Copyright © 2009 by Helene G. Kershner What is AI? In the 1950s, scientists thought artificially intelligent machines were just around the corner. Clearly R2D2 & C3PO have yet to arrive. Computers are very good at following rules These rules can include “rules of thumb” called heuristics Good at playing games, Chess, GO So good in fact that in 1997, Deep Blue a computer chess program won a series of chess games against the human world champion of chess Gary Kasparov Largely used brute force But, Games are not the only things that have rules! Copyright © 2009 by Helene G. Kershner What is AI? What else has rules? Grammar Spelling Some Medical diagnosis Drug interactions Blood tests Certain common illnesses Spam filters Web searches Programs to catch “cheaters” in school such as “TurnItIn” and “Moss” Copyright © 2008 by Helene G. Kershner What is AI? – Expert Systems Expert Systems Software that attempts to duplicate the ways in which professionals make decisions are called expert systems. An expert is a specialist in a specific, often narrow field who has gained an incredible amount of knowledge about this narrow field A surgeon who specializes in sports medicine National expert in the US Tax Code A group of oncologists specializing in drug side effects Copyright © 2008 by Helene G. Kershner Expert Systems EasyDiagnosis – provides online analysis of important medical symptoms in a user-friendly format. http://easydiagnosis.com/ CADUCEUS (expert system) - Blood-borne infectious bacteria Dendral – Helps organic chemists identify unknown molecules Dipmeter Advisor - Analysis of data gathered during oil exploration Mycin - Diagnose infectious blood diseases and recommend antibiotics (by Stanford University) XCON formerly R1 (for eXpert CONfigurer)- Order processing SHINE Real-time Expert System – An expert system for writing expert systems developed by NASA STD Wizard - Expert system for recommending medical screening tests http://www.stdwizard.org/ *http://en.wikipedia.org/wiki/Expert_system Copyright © 2009 by Helene G. Kershner AI – Expert System Program Knowledge base of rules Inference Natural Expert Language Interface Engine Database of facts User http://www.cs.cf.ac.uk/Dave/AI1/mycin.html Copyright © 2009 by Helene G. Kershner AI – Expert System Example from Mycin When the system is in Consultation mode the user interacts with the system by entering data in English. Based on the data provided the inference engine (IF/Then/Else rules) derives an answer to the question posed by the user. The role of the inference engine is to search for facts that match the conditions set up by the questions and answers. The kinds of questions and answers that can be used are limited to the realm of the system. http://www.cs.cf.ac.uk/Dave/AI1/mycin.html Copyright © 2009 by Helene G. Kershner AI – Expert System Mycin – a sample System: What is the patient's name? User: George Washington System: What is the patient's age? User: 254 years System: Is the patient male or female? User: Male System: What are the symptoms? User: Headache dizziness upset stomach high fever System: When did these symptoms first appear? User: December 13,1799 System: I conclude that the patient has a viral infection , my recommendation is that he should take two aspirin, drink plenty of fluid, get lots of rest and call me in the morning. Fact: George Washington died the next day of a viral infection, no antibiotics Copyright © 2009 by Helene G. Kershner What is AI? What about common sense? Computers are TERRIBLE at this! Humans are awesome at this. Common sense requires “rules of thumb” (Heuristics) for ordinary things. Talking and chewing gum at the same time What is time? Where we are in “space” in relation to other objects The nature of physical object How not to crush a light bulb How objects interact How people interact Copyright © 2008 by Helene G. Kershner What is AI? – Common Sense Reasoning CYC and Doug Lenat EnCYClopedia of everyday rules of how the world works Applications to everything Military Medical Transportation system Air traffic control Incredibly complex and difficult Ongoing project by CYCorp Copyright © 2008 by Helene G. Kershner What is AI? “Does AI aim to put the human mind into the computer? Some researchers say they have that objective. But maybe they are using the phrase metaphorically. The human mind has a lot of peculiarities, and I'm not sure anyone is serious about imitating all of them.” http://www-formal.stanford.edu/jmc/whatisai/node1.html Copyright © 2009 by Helene G. Kershner AI – Why is this so Hard? Human recognition software and artificial intelligence http://www.youtube.com/watch?v=OiqJ-lpnD-U Does AI mean we mimic how humans do things OR is AI a computer duplicating a task humans do only doing it using a different technique? Robot vacuum AI as science vacuums the floor doesn’t perform the task in the way a human would do it does it matter? Involves -- Cognitive Science – how the human brain works AI as Engineering – solves a problem, but may not use a human solution and doesn’t care. Copyright © 2009 by Helene G. Kershner AI – Why is this so Hard? Some AI scientists are trying to understand the “nature” of intelligence. Can be viewed as understanding the science of intelligence Other AI scientists are trying to “mimic” intelligence. Can be viewed as engineering or designing a machine that does what humans do but probably in a different way. Copyright © 2009 by Helene G. Kershner