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Sunrayce '93

The Turing Test

Battle of the Crazy Machines

Human-Powered Submarines

Contest Extra
in the classroom

The Turing Test

Are computers really as intelligent as we think? In 1950, British mathematician Alan Turing proposed a way to answer the question, "Can computers think?" Turing designed a contest that required a human judge to question a computer and a person. If the computer fools the judge into believing it's human, then the machine could be said to be intelligent. Join Frontiers for this historic demonstration of the Turing Test, part of the continuing quest to develop artificial intelligence.

Curriculum Links
Notes & Discussion
Who Was Alan Turing?
Activity 1: Debate...Contemplate...Speculate
Activity 2: The Electronic Brain
Literature Connections
Fast Fact



nervous system

artificial intelligence,
expert systems


logical operation


science fiction

  • The competition seen on this segment was sponsored by New York businessman Hugh Loebner, who modeled it on Turing's theory of machine intelligence. The winner of this limited Turing Test was Joseph Weintraub's PC Therapist III software, which fooled several judges into thinking it was human.

  • What is artificial intelligence? According to one definition, it is the "science of making machines do what would require intelligence if done by a person." Do students agree? Is a Turing Test sufficient to judge computer intelligence?


Turing was a brilliant mathematician and computer pioneer who lived and worked in England (1912-54). During World War II, he was part of a top-secret operation that helped crack the Nazi codes. Early in his career, he designed a hypothetical Turing machine that later became the basis for much of computer science -- at a time when computers took up the space of several rooms and ran on vacuum tubes. He and his colleagues developed the Colossus, the first electronic computer. Turing strove to develop a computer that would simulate human thought. His interesting life has been the subject of biographies and a play.

"Many people say a computer can only do what it's been told to do. Well, it's true, it may start off that way, but it is only the start. A computer can be made to learn."

-- Dialogue attributed to Alan Turing, speaking in Breaking the Code, a play by Hugh Whitemore

  • In the information age, new technology raises many questions about the role of computers in our lives. Scientists, philosophers and humanists are engaged in ongoing dialogue about the nature of intelligence, how the brain works and the relationship of people to machines. College courses and professional journals are tackling such complex issues as those described below. Choose topics to debate and simulate a panel of experts from science and the arts.

  • What impact will electronic and online capabilities have on the print publishing industry (newspapers, magazines, books)?

  • MIT computer scientist Joseph Weizenbaum worries that people are too willing to accept the expertise of computers without question. Do people overestimate the intelligence and capabilities of computers?

  • Do computers threaten our way of life? For example, some musicians fear that digitized sound could mean the end of live music and that computerized piano tutorials will mean the end of piano teachers.

  • What advantages do computers have over humans; i.e., what tasks do machines perform better than people?

  • What happens when the lights go out? By allowing technology to take over certain mental functions (spelling, calculating), are we developing too great a reliance on machines?

  • What advances in business, medicine and science would have been impossible without the computer?

  • At what point does a computer become "human?" If it's judged intelligent and capable of thinking, would it be a crime to unplug it?

  • Computer science pioneer Marvin Minsky believes that we can and should program emotions into computers. Do you agree? Why or why not? What advantages/disadvantages would emotions contribute?


Ever wish you had a machine to do your work? Here's your chance -- but you must program it first! Engage your mind with these questions and activities.

Design an Expert System
  • Expert systems, a product of artificial intelligence research, are widely used. They can diagnose diseases and locate mineral deposits successfully. Using online or library research, how many other examples of expert systems can you find? How much of the computer technology in your home uses elements of expert systems or artificial intelligence, also called AI? Don't forget your car, kitchen appliances and security devices.
"Expert systems are knowledge-based programs for computers. What we call computer hardware is the machinery that just sits there. Turn off the electricity switch and all you have are a lot of expensive paperweights."

-- from The Turing Option

  • Computers are great at number-crunching and data processing, but they cannot perform simple tasks humans do almost automatically. Write a step-by-step program that would tell a robot how to tie a shoe.

  • One of the first artificial intelligence programs was developed to play checkers. With a partner, play a game of checkers and write down all the possible moves you think of when it's your turn.

  • If you could design an expert system, what would it do? What would it have to know before completing its task?

  • In July 1993, some of the smartest robots gathered in Washington, D.C., for a contest sponsored by the American Association for Artificial Intelligence. Some used TV cameras for vision and compasses for navigation. Use your imagination to design a robot that would obey your commands. What technology would you use? What information would your robot need?

  • In The Difference Engine, a novel by William Gibson and Bruce Sterling, computers are operational in Victorian England. What impact might computers have had on the Civil War or some other historic era? Write a short story placed in the past but imagine that computers have already been invented.

  • The Turing Option, a sci-fi novel by Harry Harrison and Marvin Minsky, is the story of a man whose brain is blown away by industrial saboteurs who steal his AI research. The hero's brain is reconstructed by connecting it to a very advanced computer and reprogramming it. Is implanting computer chips in the human brain plausible? Desirable?

  • What is the future of virtual reality? In Testing, by Charles Oberndorf, high school students undergo "dreamchair testing" using the technique. Instead of reviewing SAT questions on their home computers, they participate in simulated moral dilemmas, such as whether to kill an innocent man to save a town. Answers determine their fate in society.

  • As computers become more intelligent, will people become more like machines, or will a truly intelligent computer force people to become smarter? Imagine a community where the computers take over and people do the work of machines, then write a story about it.

  • If you're a hobbyist interested in building an expert system, or in learning more about AI, consult AI: The Tumultuous History of the Search for Artificial Intelligence (Basic Books). You might consider learning LISP or Prolog and acquiring the appropriate compiler or interpreter software.

  • The human brain is vastly more complicated than any computer. The brain consists of about 100 billion neurons wired together into a complex network of about 100 trillion connections. By one estimate, to generate the raw computing power equivalent to a single human brain, we would have to link up 1,000 Cray-3 supercomputers, at a cost of $20 billion!


Scientific American Frontiers
Fall 1990 to Spring 2000
Sponsored by GTE Corporation,
now a part of Verizon Communications Inc.