Alan Turings method - Essay Example

Alan Turing’s method ABSTRACT Alan Mathison Turing was an English mathematician, logician, and cryptographer. He is often considered to be the father of modern computer science as he has contributed immensely towards the field of computer science through his Turing test. Though not considered a philosopher, he is cited by many modern day philosophers. The Turing Test which is named after him is the most significant contribution he has made in the world of modern computers. Though there are many who has opposed this test, it has undoubtedly a turning point in today’s world. In a very short span of life, Alan Turing has provided significantly. This paper describes briefly Alan Turing’s Life and his achievement through the Turing Test. This paper also gives a brief overview of the future that this test holds and concludes that the Turing Test has been, and will continue to be, an influential and controversial topic. Introduction Alan Mathison Turing was an English mathematician, logician, and cryptographer and he was an original thinker. He is often considered to be the father of modern computer science as he has contributed immensely towards the field of computer science through his Turing Test. Even though Turing never designated himself as a philosopher, his 1950 paper "Computing Machinery and Intelligence" is most frequently cited in modern philosophical literature as it gave a new approach to the traditional mind-body problem, by connecting it to the mathematical concept of computability (Hodges, 2002). Today, it is well known fact that the Turing Test is one of the most discussed topics in artificial intelligence, philosophy of mind, cognitive science, and mechanical science. This paper describes in detail about the life of Alan Turing and also how his Turing test has an influence in the modern science. Besides, in this paper Turing’s ideas are discussed in detail and also present the important comments made by many philosophers and others. Turing’s test and criticism by different people are also discussed. Finally, the paper concludes looking at the future applications of Turing’s test and looks at the current situation and analyzes programs that have been developed with the aim of passing the Turing Test. Alan Turing Life Alan Mathison Turing was born to an upper middle class British family in London, 23 June 1912. He was educated at Sherborne School. While in his school, he was criticized for his handwriting by his teachers. He also struggled at English and mathematics as he was too involved with developing his own ideas to produce solutions to problems using the methods taught by his teachers. From his early years of schooling he has amazed many of his teachers. He tried to always find his own solutions and in spite of producing unconventional answers, Turing did win almost every possible mathematics prize while at Sherborne. This has amazed many of his teachers. The one subject he liked was chemistry. However from a very early age, he carried out experiments following his own plan which did not please his chemistry teacher. As a result of these Turing's headmaster once wrote:- “If he is to stay at Public School, he must aim at becoming educated. If he is to be solely a Scientific Specialist, he is wasting his time at a Public School”. In spite of the difficult schooling years, Turing entered King's College, Cambridge, in 1931 to study mathematics. He had a much easier time in college than in school as he could explore more of his own ideas in college. Turing studied mathematics with increasing distinction and as a result of his academics he was elected a Fellow of the college in 1935. The paper "On Computable Numbers with an application to the Entscheidungsproblem" (Turing 1936-37) was his first and perhaps greatest success. In this paper he gave a definition of computation and an absolute limitation on what computation could achieve, which makes it the beginning work of modern computer science. For the first time in this paper he introduced an abstract machine, which is now called a "Turing machine". Turing defined a computable number as real number whose decimal expansion could be produced by a Turing machine starting with a blank tape. This work led him to Princeton for more advanced work in logic and other branches of mathematics. One of his major publications from Princeton was of great significance Systems of Logic Based on Ordinals which was published in 1939 (Connor and Robertson, 2003). He return to Britain in 1938, and was immediately recruited for the British communications war. From the year 1939 to 1945, Turing was mostly engaged in the mastery of the German enciphering machine, Enigma, and other cryptological investigations at Bletchley Park, which is the British government's wartime communications headquarters. Here again his expertise was taken into account and Turing made an exceptional logical contribution to the decryption of the Enigma. This gave him recognition as the chief scientific figure, with a special responsibility for reading the U-boat communications. These experiences and his basic interest in innovation made him to pursue his long term vision. Integrating his ideas from mathematical logic, his experience in cryptology, and some practical electronic knowledge, he wanted to create an electronic computer. However, he could not gain much success and frustrated in his work, he emerged as a powerful marathon runner, and was almost qualified for the British team in the 1948 Olympic Games. He was a member of Walton Athletic Club and he won their 3 mile and 10 mile championship in record time. He also ran in the A.A.A. Marathon in 1947 and was placed fifth (Connor and Robertson, 2003). Turing's motivation towards scientific field was always growing. He soon returned to the theoretical limitations of computation and he focused on the comparison of the power of computation and the power of the human brain. His argument was that the computer, when properly programmed, could be equivalent to the human brain. Later in 1948 he moved to Manchester University. While in this university, he wrote his famous 1950 paper, "Computing Machinery and Intelligence," (Turing 1950). In the year 1951 he was elected a Fellow of the Royal Society for his 1936 achievement. However, he now focused on a new idea of mathematical theory of biological morphogenesis (Turing 1952). Unfortunately, this was the time when the greatest tragedy occurred in his life when Alan Turing's arrest in February 1952 for his sexual affair with a young Manchester man. As ever Turing was decades ahead of his time and was relatively open about his sexuality. But at that time a homosexual relationship was a crime and a scandal. He was obliged, to escape imprisonment, to undergo the injection of oestrogen intended to wipe out his sexual drive. He decided to submit to hormone treatments rather than go to prison. He was injected with the female hormone estrogen as it was believed that estrogen injections were useful in curbing sexual urges. Besides, as a result of this event he was banned from continuing secret cryptological work. His general broad-minded attitude was enhanced rather than buried by the criminal trial, and his intellectual uniqueness also remained as lively as ever (Hodges, 2002). He had kept cyanide in the house in connection with chemical experiments. But ultimately he committed suicide by eating an apple laced with cyanide in 1954 when he was just 41 years old. He would have definitely made serious changes in the world if he had been alive. Turing Test and its Development The Turing test named after Alan Turing is a proposal for a test of a machine's capability to demonstrate thought which is equal or superseded human thoughts. This machine was described by Professor Alan Turing in the 1950 paper "Computing machinery and intelligence". The basic idea behind the test was, a human judge engages in a natural language conversation with two other parties, one a human and the other a machine; if the judge cannot reliably tell which is which, then the machine is said to pass the test (Reus and Hutman, N.D). Turing predicted that machines would sooner or later be able to pass the test. In fact, he predicted that by the year 2000, machines with 109 bits (about 119MB) of memory would be able to fool 30% of human judges during a five-minute test. He also thought that when this comes true people would then no longer consider the phrase "thinking machine" contradictory (The Internet Encyclopedia of Science, N.D.). However, the fact is that till now no machine has passed this test. The test was inspired by a party game known as the "Imitation Game", in which a man and a woman go into two different rooms, and guests try to tell them apart by writing a series of questions and reading the typewritten answers sent back. In this game, both the man and the woman aim to convince the guests that they are of the other gender. Turing proposed a test employing the imitation game as follows: "We now ask the question, 'What will happen when a machine takes the part of A in this game?' Will the interrogator decide wrongly as often when the game is played like this as he does when the game is played between a man and a woman? These questions replace our original, 'Can machines think?' (Turing 1950) Later in the paper he suggested an "equivalent" alternative formulation involving a judge conversing only with a computer and a man. In recent years many programs are developed to prove the statement that machines may also think. A machine may well be intelligent without being able to chat like a human. For instance, simple conversational programs, such as ELIZA, have fooled many people to think that they are talking to another human being. However it is important to note that such limited successes does not qualify passing the Turing test (The Internet Encyclopedia of Science, N.D.). It is a well known fact that Turing initially proposed the test in order to replace the emotionally charged and meaningless question "Can machines think?" with a more well-defined one. The advantage of the new question, he said, was that it "drew a fairly sharp line between the physical and intellectual capacities of a man." Turing Test: For and Against There were many who criticized Turing test and many who were for the test. For instance, Mays (1952) who wrote one of the earliest replies to Turing, questioning the fact that a machine designed to perform logical operations could actually capture “our intuitive, often vague and imprecise, thought processes.” “Defenders of the computing machine analogy seem implicitly to assume that the whole of intelligence and thought can be built up summatively from the warp and woof of atomic propositions.”16. In Scriven’s (1953) first article he arrived at the conclusion that merely imitating human behaviour was certainly not enough for consciousness. Then, a decade later, apparently seduced by the claims of the new AI movement, he changed his mind completely, saying: “I now believe that it is possible so to construct a supercomputer as to make it wholly unreasonable to deny that it had feelings” (Anderson, 1964). Gunderson (1964, 1967) believed that passing the Turing Test would not necessarily be a proof of real machine intelligence. Moor (1976) agreed that passing the test would constitute a sufficient proof of intelligence. He viewed the Test as “a potential source of good inductive evidence for the hypothesis that machines can think,” rather than as a purely operational definition of intelligence. However, he suggested that it is of little value in guiding real research on artificial intelligence. Stalker (1978) replied that an explanation of how a computer passes the Turing Test would require an appeal to mental, not purely mechanistic notions. Moor (1976) countered that these two explanations are not necessarily competitors. Turing himself suggested several objections which could be made to the test. For instance in the first proposal of the test he raises objections such as heads in the Sand objection, mathematical, mechanical, data processing objection, argument from consciousness, theological objection, Lady Lovelace objection and extra-sensory perception. The following are the brief descriptions of the objections and replies from the article in which Turing first proposed the test: In the 'Heads in the Sand' Objection, Turing stated that 'the consequences of machines thinking would be too dreadful. Let us hope and believe that they cannot do so.' Mathematical objections mainly use mathematical theorems, such as Gödel's incompleteness theorem, to demonstrate that there are limits to what questions a computer system based on logic can answer. For this objection Turing suggests that humans are too often wrong themselves and pleased at the unreliability of a machine (Turing, 1950). Turing proposed that a sufficiently fast machine with adequately large memory could be programmed with a large number of human questions and human responses to deliver a human answer to almost every question and a vague random answer to the few questions not in its memory. This would simulate human response in a purely mechanical way. This was the mechanical objection that was raised. Data Processing Objection claims that machines process data bit by bit where as humans process data holistically. Argument from consciousness is suggested by Professor Geoffrey Jefferson in his 1949 Lister Oration, entitled, "The Mind of Mechanical Man," which states that "not until a machine can write a sonnet or compose a concerto because of thoughts and emotions felt, and not by the chance fall of symbols, could we agree that machine equals brain." For this argument Turing replies by saying that we have no way of knowing that any individual other than ourselves experiences emotions, and that therefore we should accept the test. Theological Objection states that thinking is a function of man's immortal soul and therefore a machine could not think. Turing replies to this objection by saying that he sees no reason why it would not be possible for God to grant a computer a soul if He so wished. Lady Lovelace Objection is one of the most famous objections and states that computers are incapable of originality as according to Ada Lovelace, machines are incapable of independent learning. However, Turing contradicts her by arguing that Lady Lovelace's assumption was affected by the context from which she wrote. But if exposed to more contemporary scientific knowledge, it would become obvious that the brain's storage is quite similar to that of a computer. While taking about the extra-sensory perception, Turing seems to suggest that there is evidence for extra-sensory perception. But he feels that conditions could be created in which this would not affect the test and so may be disregarded (Turing, 1950). Differences between Computer and Human Decades have passed after the Turing test has been proposed and there is still no machine that has passed the Turing test. There is no doubt that the difference between a computer and a human is obvious. It has been argued that the Turing test is so defined that it cannot serve as a valid definition of machine intelligence or "machine thinking" for at least the following three reasons: even if a machine passes the Turing test and may be able to simulate human conversational behaviour, still this may be much weaker than true intelligence of a human being. The machine might just follow some cleverly devised rules. Secondly a machine may very well be intelligent without being able to chat like a human. And thirdly many humans that we'd probably want to consider intelligent might fail this test e.g., the children or the illiterate or less educated people. Where as, the intelligence of fellow humans are almost always tested exclusively based on their speech. Additionally, there is yet another problem that even if the Turing test is a good operational definition of intelligence, it may not indicate that the machine has consciousness. Possibly intelligence and consciousness, are such that neither one necessarily implies the other. Hence it can be said that the Turing test might fail to capture one of the key differences between intelligent machines and intelligent people. Future of Turing Test It is more than half a century passed after the Turing Test, initially proposed as a simple operational definition of intelligence. The changing perception of the Turing Test over the years has simultaneously paralleled the changing attitudes in the scientific community towards artificial intelligence. Hence it can be concluded that with the prediction that the Turing Test will remain important even in the future. Machines will be developed in such a way to pass the Turing test and it will be a landmark in the history of the development of intelligent machines. Additionally it will be of great relevance to the future generations as the cognitive capacities of machines will be immensely greater than they presently. Turing test is of great significance in the past and will remain in the future. Conclusion Though Alan Turing was a failure in his life as he committed suicide; his scientific contribution will remain to be of great significance. The future developments in the field of computer science will try to pass the Turing test and will prove to be of great significance to human beings. It is now more than half the century that Turing Test has been the subjected to debate and controversy. From its very beginning, the Test has come under serious criticism of various sorts. However, it is certain that as the days pass by human beings are moving into a world where machines will play a major part in all of the activities. Though it may me highly difficult for robots to perfectly simulate human beings, they may be developed to match the human capabilities and may pose certain ethical dilemmas for us. References Connor, J.J.O. and Robertson, E.F. (2003) Alan Mathison Turing, MacTutor History of Mathematics, Retrieved on 12 August 2007 from http://www-history.mcs.st-and.ac.uk/Mathematicians/Turing.html Gunderson, K. (1964) The imitation game. Mind, 73: pp234-245. Gunderson, K. (1967) Mentality and Machines. Doubleday. Hodges, A. (2002) Alan Turing, Stanford Encyclopedia of Philosophy, Metaphysics Research Lab, Retrieved on 13 August 2007 from http://plato.stanford.edu/entries/turing/ Mays, W. (1952) Can machines think? Philosophy, 27: pp148-162. Moor, J. (1976) An analysis of the Turing Test. Philosophical Studies, 30:249-257. Reus, J. and Hutman, S. (N.D) Chatterbot – Leaving the human factor out of the equation, Retrieved on 11 August 2007 from http://www.maartenlamers.com/BNAIC2007/dereus-hutman-chatterbot2.doc Scriven, M. (1953) The mechanical concept of mind. Mind, 62: pp 230-240. Stalker, D. (1978) Why machines can't think: A reply to James Moor. Philosophical Studies, 34: pp 317-320. The Internet Encyclopedia of Science, (N.D.) Turing test, Retrieved on 11 August 2007 from http://www.daviddarling.info/encyclopedia/T/Turing_test.html Turing, A. M. (1950) Computing machinery and intelligence. Mind, vol. LIX, no. 236, October, pp. 433-460. Turing, A. M., (1952), The chemical basis of morphogenesis, Phil. Trans. R. Soc. London B 237: pp 37-72. Read More