Organization: Computing Center, Mississippi State University
Newsgroups: bit.listserv.words-l
Date:         Fri, 10 Apr 1992 20:09:33 CDT
 <WORDS-L%UGA.bitnet@VTVM2.CC.VT.EDU>
From:         Frank Peters <fwp%CC.MSSTATE.EDU@VTVM2.CC.VT.EDU>
Subject:      Re: CALLING ALL STUDENTS OF RUSSIAN
Comments: To: words-l@uga.cc.uga.edu

Oh goody!  Finally a topic that I know something about.

In article <01GIOGKF0URS95MNFL@CWU.BITNET> Lobstrosities Unite
 <CHRISS%CWU.bitnet@VTVM2.CC.VT.EDU> says:
>>Don't worry about it Natalie - in the post where Turing Machine originally
>>came up, the poster didn't know what it meant either; he seemed to be
>>equating it with a program which ran the Turing Test.  (To forestall
>>flames, yes - *any* program is reducible to a Turing machine, but that
>>wasn't what was said.)
>
>Gosh, Graham. I didn't realize we all had to speak and use the same terminology
>as do you.  Around here, Turing Machine is understood as any device that runs
>(notice I didn't say, "can run") the Turing Test.  That's how it was taught to
>me (in a basic sort of way).

Hmmm...'around here' must not include any computer scientists.  While
you are certainly free to use the term as you like, this is NOT what
people trained in computer science mean when they use the term.

Its amusing that Turing's greatest popular fame is related to AI and
the Turing Test.  Most of his work (and certainly his most useful work)
involved the field of computability and a problem commonly referred to
as the Halting Problem.

In the course of his research into computability Turing demonstrated
that any computable mathematical problem (some aren't...Kurt Godel
proved that) could be computed by a mechanical device with a certain
minimal set of features.  Note that this definition doesn't address
doing such computations in any reasonable length of time.  That is a
purely practical issue of little theoretical interest.  All the he
demonstrated was that such a device would eventually finish.

Any engine which contains this set of features is a Turing Machine.  In
a strict sense no such devices exist since a Turing Machine must have
infinite storage capacity (in order to perform any mathematical
computation no matter how complex).  But all it really takes is a
machine with some implementation of state, an input device and an An
enough storage to use as scratch space for any computation put to it.

But with this one exception the earliest vacuum tube computers more
than met the criteria for a Turing Machine.  Every computer in popular
use today (even programmable calculators) is a Turing Machine in all
but storage capacity.

The GNU emacs editor, assuming access to infinite storage, is also
a Turing Machine.

>What was Turing most noted for? I think for his statement (and subsequent
>proof, at least in his mind) that a computer, given the right environment, etc,
>could be passed off as a person.  Or, more correctly, that a subject could not
>guess, by the responses received, whether the responder was human or computer.

Turing's involvement in the field of AI was tangential.  The questions
of the theoretical possibility of AIs and how to recognize one if it
should happen to be built are distantly related to Turings field of
computability.  The theory and practice behind actually BUILDING one
didn't seem to interest him in the least.

The Turing Test was little more than an interesting mental exercise for
Turing.  Some of his research wandered over near the field of AI so he
just stopped in to say hello.  He left after that brief visit and never
went back.

>On what device did he initially run these tests?  On a Turing Machine.

There is only one Turing Test.  Turing never tried to run it.  He never
built a machine with the intention of putting it through a Turing
test.

In fact Turing didn't actually build much of anything.  He was a
mathematician whose field of mathematics happened to have strong
relevance to computer science.

>Can I suggest, Graham, that if you feel the need to show off your Public School
>Education, you try not to be such a weenie about it.

Whatever his attitude, he's right.

--
Frank Peters  -  UNIX Systems Programmer  -  Mississippi State University
Internet: fwp@CC.MsState.Edu  -  Phone: (601)325-7030  -  FAX: (601)325-8921
Comments: Gated by NETNEWS@AUVM.AMERICAN.EDU