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What is consciousness?
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Can an artificial machine really think?
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Does the mind just consist of neurons
in the brain,
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or is there some intangible spark
at its core?
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For many, these have been
vital considerations
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for the future of artificial intelligence.
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But British computer scientist Alan Turing
decided to disregard all these questions
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in favor of a much simpler one:
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can a computer talk like a human?
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This question led to an idea for measuring
aritificial intelligence
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that would famously come to be known
as the Turing Test.
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In a 1950 paper, "Computing Machinery
and Intelligence,"
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Turing proposed the following game.
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A human judge has a text conversation
with unseen players
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and evaluates their responses.
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To pass the test, a computer must
be able to replace one of the players
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without substantially
changing the results.
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In other words, a computer would be
considered intelligent
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if its conversation couldn't be easily
distinguished from a human's.
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Turing predicted that by the year 2000,
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machines with 100 megabytes of memory
would be able to easily pass his test.
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But he may have jumped the gun.
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Even though today's computers
have far more memory than that,
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few have succeeded,
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and those that have done well
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focused more on finding clever ways
to fool judges
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than using overwhelming computing power.
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Though it was never subjected
to a real test,
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the first program with
some claim to success was called Eliza.
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With only a fairly short
and simple script,
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it managed to mislead many people
by mimicking a psychologist,
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encouraging them to talk more
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and reflecting their own questions
back at them.
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Another early script, Parry,
took the opposite approach
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by imitating a paranoid schizophrenic
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who kept steering the conversation
back to his own preprogrammed obsessions.
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There success in fooling people
highlighted one weakness of the test.
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Humans regularly attribute intelligence
to a whole range of things
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that are not actually intelligent.
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Nonetheless, annual competitions
like the Loebner Prize,
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have made the test more formal
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with judges knowig ahead of time
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that some of their conversation partners
are machines.
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But while the quality has improved,
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many chatbot programmers have used
similar strategies to Eliza and Parry.
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1997's winner, Catherine,
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could carry on amazingly focused
and intelligent conversation,
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but mostly if the judge wanted
to talk about Bill Clinton.
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And the more recent winner,
Eugene Goostman,
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was given the persona of a
13-year-old Ukranian boy,
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so judges interpreted its nonsequiturs
and awkward grammar
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as language and culture barriers.
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Meanwhile, other programs like Cleverbot
have taken a different approach
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by statistically analyzing huge databases
of real conversations
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to determine the best responses.
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Some also store memories
of previous conversations
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in order to improve over time.
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But while Cleverbot's individual responses
can sound incredibly human,
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its lack of a consistent personality
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and inability to deal
with brand new topics
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are a dead giveaway.
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Who in Turing's day could have predicted
that today's computers
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would be able to pilot spacecraft,
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perform delicate surgeries,
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and solve massive equations,
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but still struggle with
the most basic small talk?
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Human language turns out to be
an amazingly complex phenomenon
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that can't be captured by even
the largest dictionary.
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Chatbots can be baffled by simple pauses,
like "umm..."
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or questions with no correct answer.
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And a simple conversational sentence,
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like, "I took the juice out of the fridge
and gave it to him,
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but forgot to check the date,"
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requires a wealth of underlying knowledge
and intuition to parse.
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It turns out that simulating
a human conversation
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takes more than just increasing
memory and processing power,
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and as we get closer to Turing's goal,
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we may have to deal with all those big
questions about consciousness after all.