From: epstein@sunc2.cs.uiuc.edu (Milt Epstein)
Subject: Re: Ambiguity a goal of language
Reply-To: epstein@cs.uiuc.edu
Organization: University of Illinois at Urbana-Champaign
Date: Thu, 9 Apr 1992 04:59:46 GMT

In <70140@bcsaic.UUCP> rwojcik@atc.boeing.com (Richard Wojcik) writes:

>Our Usenet feed is quite sporadic, so I didn't get to see all of Herman's
>original post.  It is absolutely true that ambiguity can be the cause of
>communication difficulty.  However, my point was that ambiguity plays the
>functional role of allowing the linguistic system to be relatively compact.
>Virtually every linguistic expression conveys different meanings in different
>contexts.  That's another way of saying that no linguistic expression is
>unambiguous.  The problem arises when the expression carries more than one
>*viable* interpretation in the same context, and at least one of those
>interpretations is unintended by the speaker.  I could argue with Herman over
>how frequent this is, but I'm not about to get into such an argument with a
>statistician.  :-) I would just say that, given the tremendous amount of
>ambiguity that you find in linguistic expressions (considered out of context),
>it is amazing that there is so little miscommunication.  We don't normally
>perceive the ambiguity, because our minds quickly arrive at a single
>interpretation without apparent effort.  What this means, is that the speaker
>knows how to construct utterances so that they fit neatly into contexts, and
>the hearer knows how to use contexts to find viable interpretations.
>
>If you work the problem of trying to get a computer to generate text so that
>it appears to be unambiguous to a reader, or to extract the contextually
>viable interpretations from text, you come to appreciate the complex balancing
>act that the mind plays when uses language.  It is too easy to construct
>expressions that overcompensate for clarity, that lack compactness of
>structure.  It is also too easy to construct expressions that undercompensate
>for clarity, that lack sufficient structure to be perceived as having one
>viable interpretation.  So the mind possesses tools for both building and
>reducing structure.  Ambiguity is a design feature of language, not a flaw.

I agree with pretty much everything that is stated in the above
paragraphs, with the exception of the following two statements.

     >However, my point was that ambiguity plays the functional role
     >of allowing the linguistic system to be relatively compact.

     >Ambiguity is a design feature of language, not a flaw.

These still trouble me, and I'm wondering if they're not a confusion
of cause and effect.  What evidence is there that ambiguity is a
design feature of language?  Is it not just as plausible to say that
since we are able to deal very well with ambiguity in language, there
was never any pressure for language to evolve to not be ambiguous?  Or
perhaps even that it is not possible for language to be unambiguous,
but that is not a problem for us in comprehension and production, and
ambiguity is just a nice feature that people take advantage of (as
opposed to it being a design feature).

I am not sure which of these positions I hold right now (or if there
are other possibilities) -- my thinking on it is still a little fuzzy,
and I will think about it some more.  At first I was leaning towards
the last of these three positions -- thinking in terms of the
constraints necessary on language for it to be learnable, and that the
additional complexity of it being unambiguous might make it
unlearnable (and hence impossible).  I'm not sure if this makes
complete sense, however.  Still, when someone says that ambiguity is a
design feature of language, that doesn't make complete sense either
(and I haven't seen anything in this discussion that motivates it as a
design feature, as opposed to just a desired feature).


>Herman's point is well taken.  There is a great deal of miscommunication in
>language, and it is very easy to use ambiguity to deceive people.  But he is
>too harsh in his judgment about ambiguity (not to mention vagueness).  We all
>grumble about how politicians put it to bad use.  But we really ought to be
>fair and admit that diplomats (and politicians) often put it to good use.  Our
>own Constitution is proof of the value of ambiguity and vagueness.  There
>wouldn't be any United States if we didn't use ambiguity and vagueness as a
>vehicle for compromise.

This really addresses different issues than I mention above (i.e.
whether ambiguity is a design feature of language).  First, I have
trouble with your use of the terms "ambiguity" and "vagueness" in
reference to the Constitution.  If by "vague", you mean "more
generally applicable", perhaps that is OK.  I'm not sure that
ambiguity would be a desired property of the Constitution, however.  I
am intuitively looking at "ambiguity" as meaning having multiple
distinct interpretations, and "vagueness" or "generality" as meaning
not fully specified, so as to allow it to be applied to distinct
situations (these seem different to me).

Sorry my thinking on these topics is not so clear -- I haven't sorted
all these things out yet, but I thought this would serve to keep the
discussion going some more.

-- 
Milt Epstein
Department of Computer Science
University of Illinois
epstein@cs.uiuc.edu