Intelligence and the Chatterbots

Introduction
The question of whether machines can accurately simulate human life has fascinated man for the past two centuries. Beginning with simple automatons in the later half of the eighteenth century such as Vaucanson's duck and his flute player, people have been creating ever more ingenious machines and artifacts attempting not just to demonstrate the inner workings and processes of animals, but also to gain a deeper understanding of what exactly it is that separates man from the machine. A common answer to this question is 'intelligence', a quality associated with learning, reasoning and an aptitude for grasping truths. Computers over the last fifty years have exhibited several of these qualities, perhaps the most famous instance being the famous loss of chess grandmaster Gary Kasparov at the hands of the supercomputer Deep Blue in May 1997. But wasn't the computer just following a sequence of step by step instructions? Could this truly be considered 'intelligence'? In 1950, a scientist came up with a definitive criterion for intelligence (no, it wasn't the IIT-JEE). It is called the Turing Test.

Turing Test
In his seminal paper titled 'Computing Machinery and Intelligence', Alan Turing considered the question of whether machines could think. Straying from the usual approach to such a question which involves formally defining a 'machine' and 'intelligence',he instead asked - 'Can machines do what we (thinking entities) can do ?'. The test he uses to decide this proceeds as follows (taken from Wiki) -

"A human judge engages in a natural language conversation with one human and one machine, each of which tries to appear human. All participants are separated from one another. If the judge cannot reliably tell the machine from the human, the machine is said to have passed the test. In order to test the machine's intelligence rather than its ability to render words into audio, the conversation is limited to a text-only channel such as a computer keyboard and screen."

The above test has proven to be influential and has also been widely criticized, but is an essential concept in the philosophy of artificial intelligence.
Turing predicted that by the year 2000 , computers with upto 120 Megabytes of memory (we now have 3000 times that much) would be able to fool thiry percent of human judges in a five mintue test. Upto now, no computer has passed the test. In fact there is a $20,000 prize offered for the first computer to pass the Turing Test. This goes to show how effective a metric Turing's Test is for defining intelligence and just how far computers still have to go to be considered smart (let alone take over the world).

The First of Many

Partly out of an attempt to pass Turing's Test, and partly just for the fun of it, there arose in the 1970s several programs that tried to cross this first human-computer barrier: language. The programs were usually simplistic in design and relied on large databases, string matching algorithms and the formal rules of English grammar to try to convincingly interact with humans. While most were woefully inadequate, some grew to tremendous popularity. Perhaps the most famous such program was Joseph Weizenbaum's ELIZA, a simulation of a psycotherapist. Using almost no information about human thought or emotion, ELIZA sometimes provided a startlingly human-like interaction. It was unnerving for several people just as Vaucanson's Duck or The Turk had been in their era, and was the first of several Chatterbots. Over the years several better and cleverer ChatterBots such as PARRY and Jabberwacky have emerged and ELBOT for one missed Alan Turing's 30% threshold by a whisker in October 2008.

Chat with ELBOT here (it's quite fun actually):
http://elbot_e.csoica.artificial-solutions.com/cgi-bin/elbot.cgi?START=normal



Turing Tests in daily life
CAPTCHAs are a kind of reverse Turing Test, one where a human has to convince a computer that he is indeed a human. In fact, CAPTCHA is an acronym for Completely Automated Public Turing Test to tell Computers and Humans Apart.



The Turing Test has become commonplace in computer jargon, and frequently features in popular webcomics, such as xkcd.


Is this really intelligence?
Over the years, there have been several criticisms of the Turing Test, saying that it does not actually measure intelligence. Perhaps the most famous argument is John Searle's Chinese Room Argument in which he asserts that understanding is essentially different from thinking. A machine passing the Turing Test of a Chinese speaker, is merely simulating the ability to understand Chinese and does not literally understand it (the actual argument is more rigorous and formal than that). Others reason that human behaviour and intelligent behaviour are not exactly the same thing since - some human behaviour is intelligent, and some intelligent behaviour is inhuman. For these reasons, the Turing Test is not really relevant.

Final take
In my opinion, intelligence is too complex and abstract a concept to be defined in a single line or using a set of symbols. We can merely attempt to learn more about its nature through experimentation with the different aspects of intelligence that we perceive around us. Jessica Riskin is right - from Vaucanson's Duck to Elbot, our best tool to understand human life has remained the same - simulation.

References:
[1] The Defecating Duck, or the Ambiguous Origins of Human Life - Jessica Riskin
[2] http://en.wikipedia.org/wiki/Artificial_intelligence
[3] http://en.wikipedia.org/wiki/Turing_test
[4] http://en.wikipedia.org/wiki/ELIZA
[5] http://www.elbot.com/
[6] http://en.wikipedia.org/wiki/Chinese_room

Fun facts:
Alan Turing, a famous cryptanalyst, logician and computer scientist - was born in Orissa.
He cracked the complex Enigma code in World War 2, helping the British intercept and decode secret German communications.
In 1931, he solved a famous problem of computer science, by proving that there exist 'undecidable problems' - problems that computers cannot solve, given even infinite time and memory.
His powerful abstraction of the Turing Machine is central to theoretical computer science.
He committed suicide (find out why) 2 weeks before his 42nd birthday, and one of the greatest scientists of all time was lost to us prematurely.