Re: Turing Test

From: Paramanantham, Daran (
Date: Thu Feb 10 2000 - 21:40:57 GMT

Date: Thu, 10 Feb 2000 21:40:57 +0000 (GMT)
From: Paramanantham, Daran <>

> Shaw
> In his paper 'Computing Machinery and Intelligence', Turing
> considers the question 'Can machines think?'. In light of the
> ambiguity concerning the words 'Machine' and 'Think' - he proposes
> an alternative 'test' to answer the same question:

Can machines think? Can be described in terms of the 'imitation game'.

> The new form of the problem can be described in terms of a game
> which we call the 'imitation game." It is played with three
> people, a man (A), a woman (B), and an interrogator (C) who may be
> of either sex. The interrogator stays in a room apart front the
> other two. The object of the game for the interrogator is to
> determine which of the other two is the man and which is the
> woman. He knows them by labels X and Y, and at the end of the game
> he says either "X is A and Y is B" or "X is B and Y is A."
> It is A's object in the game to try and cause C to make the
> wrong identification.
> 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?"

> Shaw:
> One question that could be asked about this test is whether it is
> possible for a machine to deceive the interrogator by applying a
> (comprehensive) set of rules. Perhaps it could be argued that,
> over a long period of time, the machine would require the ability
> to 'think' in the same way as the interrogator in order to
> maintain the deception. Surely the outcome will also depend on the
> ability of the interrogator to ask appropriate questions, and on
> his or her preconceptions of how machines behave.

This game is basically some sort of test, to find out whether a machine
can deceive the interrogator and how well it does compared to a human.
The outcome relies on the quality of questions asked, and how well a
machine can learn from the questions.

> Shaw:
> With regard to the definition of the term 'Machine' in the test,
> Turing says:

> We also wish to allow the possibility than an engineer or team of
> engineers may construct a machine which works, but whose manner of
> operation cannot be satisfactorily described by its constructors
> because they have applied a method which is largely experimental

> This could be important, because it removes the requirement that
> the designer of the system should understand its working. Assuming
> that it is possible to construct a 'thinking' machine and
> establish that it can 'think' (the original problem), the engineer
> would not need to understand the thought process itself. For
> example, if a neural network of sufficient complexity could be
> constructed and trained so as to pass the Turing test, the
> designer would almost certainly be unable to explain its operation
> at a low level.

It is important to understand the working of a machine, for future
investigations, research, improvements etc. This enables designers to
enhance their understanding of machines.

> Shaw:
> Later in the paper, Turing asserts that a digital computer can
> produce the same effects as any 'discrete state machine', in which
> only two states of any element are considered, nothing in-between:

> This special property of digital computers, that they can mimic
> any discrete-state machine, is described by saying that they are
> universal machines. The existence of machines with this property
> has the important consequence that, considerations of speed apart,
> it is unnecessary to design various new machines to do various
> computing processes. They can all be done with one digital
> computer, suitably programmed for each case. It 'ill be seen that
> as a consequence of this all digital computers are in a sense
> equivalent.

> This seems to be quite a convincing argument in favour of machines
> eventually being able to think. Can't the brain be considered a
> discrete-state machine: surely a neuron either fires or it doesn't
> and it is this that determines the effect on the rest of the
> brain.

For this to be feasible, machines will have to be given a set of
training data initially. Hence, for a machine to 'think' it needs to
undergo supervised learning. If this is the case, will machines ever
be able to 'think' for themselves.

> Shaw:
> One of the arguments that Turing defends against are that machines
> will never be able to be the subject of their own thoughts:

> The claim that a machine cannot be the subject of its own thought
> can of course only be answered if it can be shown that the machine
> has some thought with some subject matter. Nevertheless, "the
> subject matter of a machine's operations" does seem to mean
> something, at least to the people who deal with it. If, for
> instance, the machine was trying to find a solution of the
> equation x2 - 40x - 11 = 0 one would be tempted to describe this
> equation as part of the machine's subject matter at that moment.
> In this sort of sense a machine undoubtedly can be its own subject
> matter. It may be used to help in making up its own programmes, or
> to predict the effect of alterations in its own structure. By
> observing the results of its own behaviour it can modify its own
> programmes so as to achieve some purpose more effectively. These
> are possibilities of the near future, rather than Utopian dreams.

> Shaw:
> Is this what is meant by 'thoughts'? Computers can alter their
> behaviour to improve some measure of performance, but they aren't
> really thinking, they are following rules. Surely to say that an
> entity is the subject of its own thought implies that it has a
> concept of itself in relation to the rest of the world. Do we
> consider animals to be the subject of their own thoughts when they
> learn to perform tasks with greater aptitude?

If a machine can 'learn' from its environment (following rules or not),
then It is said that they can think, do we (humans) follow rules and
learn from them.

> Shaw:
> Another interesting criticism is that machines can only ever do
> what we tell them, to which the answer is:

> One could say that a man can "inject" an idea into the machine,
> and that it will respond to a certain extent and then drop into
> quiescence, like a piano string struck by a hammer. Another simile
> would be an atomic pile of less than critical size: an injected
> idea is to correspond to a neutron entering the pile from without.
> Each such neutron will cause a certain disturbance which
> eventually dies away. If, however, the size of the pile is
> sufficiently increased, tire disturbance caused by such an
> incoming neutron will very likely go on and on increasing until
> the whole pile is destroyed. Is there a corresponding phenomenon
> for minds, and is there one for machines? There does seem to be
> one for the human mind. The majority of them seem to be
> "subcritical," i.e., to correspond in this analogy to piles of
> subcritical size. An idea presented to such a mind will on average
> give rise to less than one idea in reply. A smallish proportion
> are supercritical. An idea presented to such a mind that may give
> rise to a whole "theory" consisting of secondary, tertiary and
> more remote ideas.

> Shaw:
> These analogies are interesting, because human beings are
> constantly thinking in some way or another without requiring
> explicit provocation. In some cases, thought is clearly
> structured, for example when we are solving a problem, but the
> rest of the time we can decide what to devote our thoughts to,
> subject to some initial stimulus. This can result in our 'state
> of mind' changing, so that, for example, after a period of time
> with no external stimulus, our response to a question might
> change. Perhaps if a machine could be seen to exhibit this kind
> of behavior, it could be considered to be 'thinking'.

This comes back to the idea of how well a machine can interact between
Itself and the environment. Machines are known to be consistent, this
make them Correct and sound. However, if a machine was to change it's
thoughts every time it itself was in a different state, then this will
lead to scientists arguing that if a machine was able to 'think', it is
logically incorrect and unsound.

> Shaw:
> Towards the end of the paper, Turing considers the possibility of
> 'educating' a primitive machine:

> In the process of trying to imitate an adult human mind we are
> bound to think a good deal about the process which has brought it
> to the state that it is in. We may notice three components.
> (a) The initial state of the mind, say at birth,
> (b) The education to which it has been subjected,
> (c) Other experience, not to be described as education, to which
> it has been subjected.
> Instead of trying to produce a programme to simulate the adult
> mind, why not rather try to produce one which simulates the
> child's? If this were then subjected to an appropriate course of
> education one would obtain the adult brain. Presumably the child
> brain is something like a notebook as one buys it from the
> stationer's. Rather little mechanism, and lots of blank sheets.
> (Mechanism and writing are from our point of view almost
> synonymous.) Our hope is that there is so little mechanism in the
> child brain that something like it can be easily programmed. The
> amount of work in the education we can assume, as a first
> approximation, to be much the same as for the human child.

> Shaw:
> This paragraph seems to overlook some important points: The
> child's brain is presumably immediately capable of experiencing
> emotion, which must be a strong factor in determining its actions.
> This is combined with a vast array of sensory inputs which
> contribute to the child's emotional state, so that 'education'
> could not be encapsulated in a simple dialog with a teacher.
> Furthermore, the child has a strong incentive to learn: survival.
> What motivation would a machine have to learn, wouldn't it need to
> experience pleasure and pain and other emotions as well? Surely
> the ability of a machine to learn to interact with human beings
> would depend on its ability to sympathise with their situation
> through experience of similar situations - wouldn't this require
> emotion?

For a machine to learn anything it first has to be given information,
just like humans, from then on, its up to the machine on how they deal
(process)with this information. The type of information ex. pleasure,
and pain and other emotions will have to be provided. If this is
possible and a machine can learn from these and adapt, then it is
possible of machines being able to think. The main point to be made
about 'can machines think', is by how much the designers want the
machines to think? is it to increase performance or is it to imitate a

Paramanantham, Daran <>

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