Born in 1912, Alan Mathison Turing pioneered the field of digital computers. A brilliant mathematician, Turing worked for the Department of Communications in Britain during WWII and helped create a device that deciphered the German U-Boat codes. Openly homosexual, he was fired from the Department after WWII. The United States government had made the condition that homosexuals were ineligible for security clearance, and in their Cold War alliance, British Intelligence complied.
In 1952, police arrested Turing for his sexual relationship with another man. He was given the choice of prison or mandatory estrogen injections for a year. Turing chose the latter. During this time, Turing’s various research continued in quantum mechanics and pattern formation in microbiology, but he was also suffering from massive bouts of depression and violent mood swings. He died on June 8th, 1954 of cyanide poisoning, just weeks before his 42nd birthday. A half-eaten apple speckled with cyanide was found by his body, apparently so his mother would think the death was accidental. His death was ruled a suicide.
The Turing Machine
As early as 1950, Turing described how to create a machine that could solve problems and perform multiple tasks. While there were computers in the early 50s, they could only perform specific tasks and with many limitations. Turing’s machine would read simple information from a never-ending tape. This simple information would tell the machine how to perform a task. (Mathematician John von Neumann would build upon this idea and come up with the binary code of 0’s and 1’s which are the building blocks of modern programming.) Turing also conceptualized that the machine must have three parts: Store (memory), Executive Unit (central processing unit), and Control (keyboard, input device). 50 years later, and I’m typing on a machine that has these exact parts.
Alan Turing believed that artificial intelligence would be possible by the year 2000. While we’re not quite there yet, his “Turing Machine” is almost a reality. The Turing Machine is a machine that could simulate human intelligence. He described the following scenario, a variation from an old parlor game called the Imitation Game:
The Imitation Game is played with a human, a machine, and an interrogator. The interrogator stays in a different room from the other two, and his goal is to determine which is the human and which is the machine. The machine’s objective is to cause the interrogator to make a wrong identification, and the human’s objective is to help the interrogator. The interrogator can ask them any questions that will help him make his determination (questions and answers can be typed on a monitor to keep things equal). Turing asserts that if a machine can successfully imitate human behavior (and thus, the interrogator misidentifies), then a machine can think.
Think about it for a moment. This would mean the machine’s program would have to be able to carry on a conversation in real-time, be programmed to lie and make mistakes (it would be a dead giveaway if the machine gave correct answers to difficult math questions put to it), and be programmed well enough to give opinions and statements that reflect feeling and emotion (in case the interrogator asks about its favorite movie or to write a poem). While it’s hard to imagine a program that can do all this, conceptually a such-programmed machine would be intelligent according to Alan Turing. In other words, an appropriately program is a sufficient condition for thinking.
Now a machine would certainly exhibit intelligence if it could pass Turing’s Test, but is it actually intelligent itself? We’ll pick up the debate on the next page!
Hodges, Andrew. Alan Turing: A Short Biography. From http://www.turing.org.uk/turing/index.html
Patent, Dorothy Hinshaw. The Quest For Artificial Intelligence. Harcourt Brace Jovanovich, 1986, San Diego.
Turing, Alan M. Computing Machinery and Intelligence. In Mind LIX, no. 2236 (Oct. 1950): 433-60.
Turing’s Test was, and still is, very influential in AI. Programs have been created to try to pass the test, but with only narrow success. The most famous example is Eliza, a program written in the mid-1960s by Joseph Weizenbaum. Eliza was programmed to act as a psychotherapist, and would respond to patients by finding keywords in sentence structures and reflect the words back at the user. Patients were able to get more insight into themselves through this program. Here’s a very famous transcript of one of its sessions with a young woman. Eliza is in caps:
Men are all alike
IN WHAT WAY
They’re always bugging us about something or other
CAN YOU THINK OF A SPECIFIC EXAMPLE
Well, my boyfriend made me come here.
YOUR BOYFRIEND MADE YOU COME HERE
He’s says I’m depressed much of the time.
I AM SORRY TO HEAR YOU ARE DEPRESSED
It’s true. I am unhappy.
DO YOU THINK COMING HERE WILL HELP YOU NOT TO BE UNHAPPY
I need some help, that much seems certain.
WHAT WOULD IT MEAN TO YOU IF YOU GOT SOME HELP
Perhaps I could learn to get along with my mother.
TELL ME MORE ABOUT MY FAMILY
My mother takes care of me.
WHO ELSE IN YOUR FAMILY TAKES CARE OF YOU
You are like my father in some ways.
WHAT RESEMBLANCE DO YOU SEE
You are not very aggressive, but I think you don’t want me to notice that.
WHAT MAKES YOU THINK I AM NOT VERY AGGRESSIVE
You don’t argue with me.
WHY DO YOU THINK I DON’T ARGUE WITH YOU
You are afraid of me.
DOES IT PLEASE YOU TO BELIEVE I AM AFRAID OF YOU
My father is afraid of everybody.
WHAT ELSE COMES TO MIND WHEN YOU THINK OF YOUR FATHER
DOES THAT HAVE ANYTHING TO DO WITH THE FACT THAT YOUR BOYFRIEND MADE YOU COME HERE
Eliza was successful to an extent at simulating a psychotherapist. Of course certain sentences that are complicated would tie it up, and the subject could see it was just a program. The last line of the transcript, by the way, is very interesting. It seems very insightful, but by all accounts it was just luck Eliza was reflecting back something from earlier in the conversation.
More impressive than Eliza was Parry, a program made by Kenneth Colby in 1971. Parry simulated a paranoid schizophrenic, and roughly 50% of psychiatrists that spoke with it thought it was a human patient.
My personal favorite Turing Machine is Racter. Racter, created in 1980 by William Chamberlain and Thomas Etter was designed to be a storyteller, but ended up just a total goofball. While more sophisticated than Eliza program-wise, it makes quite a lot less sense. In fact, Racter writes just like me! Here’s the funny transcript of when they pitted it with Eliza:
ELIZA: HELLO. PLEASE STATE YOUR PROBLEM.
Racter: Excellent! Excuse me a minute while I attend to some business. I’ll be right back.
ELIZA: WHY DO YOU NEED TO TELL ME EXCUSE ME WHILE YOU ATTEND TO SOME BUSINESS.
Racter: Is it better to need or to despise? Why is it that I do need to tell you to excuse myself to attend to some business? Because electrons are brave. Braveness is nice, don’t you think? And the needers all insist upon it. Do you imagine I am a Communist?
There were a lot more important programs, but space is short, so I’m going to end with a transcript from Mics. Mics was developed by Jaime Carbonell in the mid-70s. Its goal was to start up a chess game, warn people about consequences of dangerous actions, and to learn about the user.
HELLO, WHAT IS YOUR NAME?
I am Dave.
WHAT’S NEW TODAY, DAVE?
Nothing. What’s your name?
MY NAME IS MICS.
What is your job?
I AM A COMPUTER PROGRAMMER.
WHAT DO YOU DO FOR A LIVING?
I am still a student.
DO YOU LIKE BEING A STUDENT?
For the time being, yes.
WHAT WILL YOU DO AFTERWARD?
I want to be a professor someday.
WHAT DO YOU DO FOR FUN?
I smoke dope.
YOU MIGHT GET STONED IF YOU SMOKE TOO MUCH.
I know, that’s the idea.
YOU MIGHT GET IN TROUBLE IF THE COPS CATCH YOU.
All right, stop moralizing, what do you do for fun?
I LIKE TO PLAY CHESS.
That sounds boring.
NO. IT IS A LOT OF FUN!
My brother Eric plays chess.
HE MUST BE SMART.
I have to go. Bye, Mics.
NICE TALKING TO YOU, DAVE.
Mics was able to remember things from past conversations and use appropriate information from those conversations for present ones.
While these programs are very sophisticated, does the machine actually understand the meanings of the words? Does it understand its own program? Read on!
Patent, Dorothy Hinshaw. The Quest For Artificial Intelligence. 1986, Harcourt Brace Janovich, San Diego.
Waldrop, M. Mitchell. Man-Made Minds: The Promise of Artificial Intelligence. 1987, Walker and Company
Weizenbaum, Joseph. Computer Power and Human Reason (New York: W.H. Freeman, 1976), pp. 3-4.