AI Expert Newsletter
AI - The art and science of making computers do interesting things that
are not in their nature.
Can Machines Think?
In 1950 Alan Turing published Computing Machinary
and Intelligence in the quarterly journal, Mind. Thanks
to the Internet, its now easy to read this original article that
is still to this day one of the defining works in AI. It is a great
In it he asked the question "Can machines think?". And
he proposed a simple test. If a human conversed, via keyboard, with
a machine and with a human, and could not tell which was which,
then that machine could be called "intelligent". This
is the famous Turing Test.
Over 50 years later, intelligent people are still debating whether
or not the Turing Test has anything to do with machine intelligence
In 1990 Hugh Loebner offered $100,000 and
a neat gold medal to the first person to write a computer program
that passed the Turing Test. There is an annual competition at which
various software authors compete for the prize.
A panel of judges carry on dialogs with a number of humans and
machines. They then rate each on a scale from most machine like
to most human like. The machine with the highest score wins the
competition. If its score is competitive with the scores received
by the humans, then the authors claim the medal and the money. If
not, they get $2,000 and everyone tries again next year.
So far, the prize has not been claimed. Some claim it can't be
done without the giant ontologies of common sense discussed last
month; others claim it requires perfecting natural language understanding;
and still others say a learning program is needed. But the best
entries so far have been based on a very simple idea.
Can Machines Converse?
In 1966 Joseph Weizenbaum described his program ELIZA.
It was a very simple pattern-matching program that generated realistic
responses to its input. It was designed to mimic a psychiatrist.
(Weizenbaum, Joseph ELIZAA Computer Program for the
Study of Natural Language Communication between Man and Machine,
Communications of the ACM, Vol. 9. No. 1 (January 1966))
For example, here's one of the ELIZA rules from one implementation
of ELIZA. (See the links for source code in
a number of languages.)
If the input had the word 'dream' in it, this rule would generate
the response, using one of the four choices. It doesn't matter what
the rest of the input was.
Think about this a second. These are pretty much the kinds of responses
one would get in a conversation when bringing up a dream.
Another powerful idea in ELIZA was pronoun swapping. In the input,
all first person pronouns became second person and visa versa. So
an input like "I remember Alaska" would match the patterns
in this rule (The 'Y' in the rules is a wild card.):
And generate a response like "Do you often think of Alaska?".
Weizenbaum was horrified at how many people enjoyed chatting with
ELIZA and that fact that even some therapists thought ELIZA was
a useful therapeautic tool. He wrote ELIZA in part to prove that
machines can NOT think. Yet people were interacting with the program
as if it could.
But who do you enjoy talking to the most? Isn't it the person who
listens, and ask questions prompting you to go on and on about yourself?
ELIZA just follows the user's lead, letting him/her talk about whatever
he/she wants. What more could someone want in a conversationalist?
What more does a therapist do?
Can People Think?
Richard Wallace, one of the developers of
A.L.I.C.E., which won the Loebner competition (not the prize, just
the most human-like of the machine contestants), observes that the
majority of casual human dialog is really just simple pattern-matching
response. He notes that people aren't really paying attention to
each other and just spitting back responses based on what's on their
mind and maybe a trigger or two from what they just heard.
The disturbing part of the debate on ELIZA is not whether it is
intelligent or not. Clearly it's not.
The disturbing question is whether ELIZA is human-like or not.
Clearly it is.
ELIZA was fun, and prompted all sorts of derivitive works, generically
called chat bots.
A.L.I.C.E. won the Loebner prize twice. It's really just a more
sophisticated version of ELIZA with a much larger set of patterns.
The development of the patterns is made easy by a standardized AI
Markup Language (AIML) that is a well-formed XML. AIML can be used
by anyone to create any sort of chat bot.
Here's some of the AIML from the winning version of A.L.I.C.E.
<pattern>HOW AM I SUPPOSED *</pattern>
<li>Think about it.</li>
<li>Don't just give up.</li>
This, of course, fits the definition of AI used in this newsletter,
which is the creation of a virtual machine to run programs written
in a language well suited for a particular domain. In this case
AIML is a perfect language for creating chat bots and an AIML runtime
makes it go.
Maybe its not significant, but I thought it was funny. Mark Humphry
wrote a chat bot to stand in his place when he was away from his
computer. Here's some rules from it that are triggered by the keyword
'Mark' in the input:
( (member 'mark input)
(mark isnt here and hes left me to deal with
cretins like you)
(forget mark i will destroy him like the others)
(mark doesnt want to talk to you fishface
why do you think im here)
(listen leave that jerk out of it talk to me)
Failing the Turing Test
Dave: Open the pod bay door HAL
HAL: I'm sorry, I can't do that Dave.
That scene from 2001 brilliantly captures all our fears of AI,
the horror of unfeeling machines empowered to run our lives.
I recently installed anti-spam software and was experiencing the
very human emotion of frustration trying to get the software to
work. I'd clearly done something simple wrong, but couldn't figure
out what. So I contacted tech support.
It was a Web site. The FAQ didn't have the answer. But they recommended
Chat with a technical support person. Sounded good, so I tried it:
Technical Support Chat: You have been connected to Sean Bourke.
Sean Bourke (S): Dennis, thank you for contacting McAfee
S: How can I assist you today?
Me (D): I just installed spam killer and don't seem to be able to
get it to work.
S: Are you receiving any error message?
D: No, I got it to work once, but it didn't filter anything.
I ran it over night, and it didn't find anything, yet when I ran
Eudora, I had tons of spam, like usual.
S: Dennis, if I understand correctly, you have the SpamKiller not
mesages. Is this correct?
D: That is almost right. It found one message a little while ago.
blue arrow in on now
S: I would be happy to assist you with that.
D: OK, so give me a starting point. Is your name ELIZA?
S: What is the version of SpamKiller that is installed on the system?
D: I just installed it from your Web site yesterday, so its the
S: Based on the information you have provided, I can now provide
steps that should resolve your issue. If at any time there is something
you do not understand, will you please stop me and let me know?
D: You didn't just type that did you? There's something non-human
S: No, I am a real person here.
D: You sound like ELIZA, give me some slang to prove you're human.
S: I am going to send you some instructions that will open a new
D: I'm reading them now, but I also do an AI newsletter and would
to write about you
(I followed the instructions, still didn't work)
D: I've been pretty frustrated, if we can't get it going I'd like
how to get a refund.
S: Could you please tell me the country you are in?
S: This issue or concern is supported by our Customer Service group.
may call 1-972-963-8000, select the option that best meets your
needs, and they will be
able to assist you.
D: What is wrong with my installation of Spam Killer?
S: Nothing is wrong. You will just need to follow a few steps to
configure the spamkiller
using the instructions that I sent you.
D: But I did that! It doesn't work.
(Called phone number, just recorded menu items, referring me back
Web page that gives me the option of this chat again or paying $39
Well, the instructions were just how to re-install, which of course
didn't work and subsequent passes through the same loop gave the
same answer, so I did the logical thing and threw my mouse across
the room and made a note not to get another radio controlled mouse.
The 5th IFAC/CIGR Workshop on Artificial Intelligence in Agriculture
will be held in Cairo on March 8-10 2004. Deadline for submitting
extended abstract is Sept. 30,2003. More Information can be found
- Abelard's Web site has a full reprint of Turing's original paper,
Computing Machinery and Intelligence, originally published
in Mind. It's a fascinating read.
- Ayse Pinar Saygin's Web site on the Turing Test. It has a number
of interesting links to background and related material.
- The home page for the Loebner Prize, which will be awarded to
the first computer that can fool a panel of judges into thinking
it is as human as humans also talking to the judges.
- An implementation of ELIZA on the Web.
- Mark Humphrys' humorous, and somewhat crude, variation on ELIZA,
called MGonz. The site includes a long dialog with the system from
someone who apparently thought it was real and full source code
in Lisp and REXX.
- CMU's AI repository page with numerous ELIZA implementations
in a variety of languages.
- Dr. Richard Wallace's excellent overview of chat bot technology
in general, A.L.I.C.E., which won the Loebner competition in 2000
and 2001, in particular, and what this all says about human intelligence.
(Most of casual human conversation is non-understanding pattern-matching
- The Web site for A.L.I.C.E.
- A directory of a number of chat bots.
- The home page for the 2002 Loebner competition.
http://www.ellaz.com/ - And
the 2002 winner is Ella, beating out notables like ALICE and Kurzweil's