From: mmt@BEN.DCIEM.DND.CA
Newsgroups: bit.listserv.csg-l
Subject: Re: code metaphor
Date: 18 Nov 92 18:58:04 GMT
Comments: Gated by NETNEWS@AUVM.AMERICAN.EDU

[Martin Taylor 921118 13:30]
(Bruce Nevin 921118 10:35:06)

>There is no warrant for claiming that perceptions associated with
>an utterance (as the meanings of the utterance) are structured in
>the way that the utterance is, and there is much to suggest that
>they are not.

In the Layered Protocol Theory (LP) the matter of structure is entirely
internal to the protocol concerned.  In LP there is no warrant for relating
the structure of any virtual message to that of another type.  They are
essentially incommensurate.

Having said that, I will back off a bit, and point out a construct we call
"global coherence".  Inasmuch as lower-level virtual messages support the
passage of higher-level ones, there will seem to be a sequential structure
if an analyst looks only at the lower-level ones.  But this structure actually
is the province of the higher-level protocol, and is, so far as the lower
one is concerned, only in the mind of the analyst.

>To see that this metaphor is wrong you have to recognize that a
>code has no information structure in it other than that imparted
>to it by the process of encoding; that is, on this view an
>utterance can exhibit only such information structure as was
>previously present in the message or belief held to be "in" the
>sender.

Technically, if I understand what you mean, that is incorrect.  But I may
be misunderstanding you, so bear with me.  In a strictly coding procedure
(no metaphor), the code may be redundant, and usually is.  Therefore the
code itself contains information relating to whether a particular received
pattern was likely to have been the one that was sent.  This kind of coding
redundancy is only possible if the encoder and the decoder contain matched
models of the coding procedure, so that the decoder can determine the
probabilities for all possible messages sent by the encoder.

Convention in communication provides to only possibility for encoding to
occur, and I identify the existence of encoding with syntactic structure.
In LP syntax is not expected to be important in face-to-face conversation
for levels much above the phrase, but it is important in going from acoustics
to phonetics, and phonetics to syllable and probably word.  It is what makes
speech recognition machines possible when they have no contextual understanding
of what the speech is for.

> If the
>structure in utterances follows from prior structure in
>perceptions to be conveyed by them as "messages," then we could
>reasonably expect languages to be alike to the extent that
>people's respective universes of perception are alike.

One would not expect this at levels below, perhaps the elements of an argument,
and probably not even there if there are conventions with respect to how
arguments are conducted.  The argument is backwards.  If there is encoding,
it is arbitrary and must have nothing to do with what is encoded, and therefore
one would expect the languages of the world to be as different as the temporal
segregation of their communities would allow.  But I would, on the other hand,
argue that the physical constraints of communication, based on informational
efficiency, constrain the kinds of differences one could find among languages.
I would think it unlikely that the parallelism inherent in perception would
be found in a kind of language that introduced a small element of every
item to be communicated at the beginning of an utterance, and added further
small aspects of every item in each small time increment, until they all
finished together.  I would expect all languages to show some pattern of
contiguity in time among items that are conceived to belong together in
perception.  After all, it is important that a warning about a tiger should
be imparted quickly, whereas the location of a nice bunch of berries can
wait.

>the particular correlations, and changes in them, are learned and
>negotiated socially, they are not byproducts of perceptual
>control.

I'd argue that the first part of this sentence is correct, the second not.
See yesterdays' discussion with Rick about "standards." I think linguistic
and other social conventions are developed in exactly the same way, by
reorganization that leads to minimum perceptual error overall.

>I suggest that it is a worthwhile challenge to formulate a brief
>statement of your Layered Protocol Theory of communication in PCT
>terms without recourse to any vestige of the message/code/conduit
>metaphor.  I think it will be stronger for the exercise.  I
>certainly will be much happier with it.

I won't do that, because, as I said, I do believe that there are social
conventions that do allow (demand) specific encoding practices, especially
at the lower protocol levels.  But if you (or anyone) is interested, I now
have annotated the slides I used for my Paris talk, and they, together with
the tutorial, provide an introduction to the way I see LP theory being linked
to PCT.  They may not satisfy you, and they are certainly not complete,
but they are an introduction to both PCT and LP as well as the link between
them (50 pages tutorial, 70 pages annotated slides, so don't ask unless you
are really interested--I will send to Bruce without him asking).

Martin
Comments: Gated by NETNEWS@AUVM.AMERICAN.EDU