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Re: Working without being ambushed by Ambiguity (was: issue-57 background reading for F2F (short required reading)

From: Graham Klyne <GK@ninebynine.org>
Date: Wed, 24 Oct 2012 23:03:49 +0100
Message-ID: <508865C5.8040206@ninebynine.org>
To: Larry Masinter <masinter@adobe.com>
CC: Pat Hayes <phayes@ihmc.us>, Tim Berners-Lee <timbl@w3.org>, David Booth <david@dbooth.org>, "www-tag@w3.org List" <www-tag@w3.org>
On 24/10/2012 21:47, Larry Masinter wrote:
 > I'm suggesting a different starting point, since the one you've been
 > using isn't working.


Hmmm... heady stuff.

I don't have the background or mental capacity to join the specifics of this 

But there's something that bothers me here with your approach.  For whatever 
it's failings, our current approach to semantics (Model Theory, which builds on 
notions of denotation) is grounded in an existing body of quite widely accepted 
theory and thought.  What you propose doesn't seem to be so grounded, so if we 
are to pursue this approach, we need to build a complete new theory building on 
personal belief and trust, and that seems to me to probably be beyond the 
capabilities of the group engaged here.  So I am inclined to see how much we can 
wring out of the theory we have.

I also question "the one [we've] been using isn't working".

In many ways, the model theoretic approach seems to work just fine.  In purely 
logical terms, it allows us to determine valid inferences without depending on 
unambiguous reference of URIs.  It's fails to associating those references with 
the imprecise but often common understanding that we as individuals may hold 
(the exact boundaries of "Everest" may be unclear, but we generally agree it's a 
high mountain in Asia, along with some common notions of "high", "mountain" and 
"Asia").  Yet for most day-to-day applications, the lack doesn't seem to matter 
(except when we come to debate what URIs might actually mean).

We seem to have two perspectives in play:  one based in logic that is precise 
but provably ambiguous, and another that is based on common perception (which I 
suppose is an extension of personal belief) but lacks rigorous inferential power.

I find myself thinking that asking which of these comes "first" is an unhelpful 
question.  Rather, we might be asking how these relate to each other; what 
correspondences might we find between the formal approach and an approach based 
in personal belief?

For general language, Quine took an approach which (as I understand) uses the 
notion of statements that most native speakers of a language agree to be true as 
the point of common reference, and showing that such truths can be preserved 
while allowing different interpretations of the underlying terms from which the 
statements are constructed.

I don't claim this is the right approach for the web and URIs, but is there an 
analogous approach that can be used?  Operationally, there are things we can say 
about URIs and HTTP and web retrieval, but they don't seem to touch logic-based 
descriptions and inference.  Yet, at another level, the referent of a URI may be 
constrained (ambiguously) by statements using that URI that people broadly agree 
to be truths - which seems rather like (my understanding of) Quine's approach.

Is it not reasonable to suggest that many URIs have commonly understood 
referents (what I have previously described sloppily as "intended meaning")? 
Where "commonly understood" might be some kind of cluster of "individual 
beliefs" which, by its nature, cannot be precisely defined.  Yet the formal 
logic works precisely because it does not command unambiguity; an inference may 
be valid for any or all denotations that fall within a common understanding -- 
and very many more that don't.


On 24/10/2012 21:47, Larry Masinter wrote:
>>> Rather than putting those off as an afterthought to be worked out later, while
>> failing to get a handle on a theory of meaning without them, they need to be
>> central.
>> All of these rest on the basic notions of a name or identifier referring to
>> something, and the truth of a proposition expressed by some sentence (or
>> "contentful structure" of some kind.)
> I don't think it's necessary to rest the layer cake on "referring to something".
> Yes, I understand that's the model you're using, where a name or identifier refers to "something" independent of the person, time, or context involved in uttering, considering, or encountering the name or identifier.   I'm suggesting a different model, where any notion of "refer" is always situated by context.
>>   We need to get the naming and the sentential structure clear before we can begin to make sense of ideas like provenance, belief or trust.
> I disagree that doing so is a "need". I understand that is the approach you're taking, and it isn't working.
> I don't think the model which starts with reference and adds provenance, belief, and trust, is adequate for the kind of analysis needed.
> I'm looking for a model that starts with reference being a personal individual act, and communication is based on correlation through turst.
>>> For example, the notion of "meaning" is tied completely to persistence.... a
>> use of a URI is "cool" to the extent that its effect on recipients (its "meaning")
>> doesn't change (over time or the range of recipients).
>> Wrong on several counts.
> I put "meaning" in quotes because I wasn't using the term in a way I thought you would agree with. Rather than argue about it, just try it out as a definition instead, change "is tied" to "should be tied".
>> Everest is a mountain, what I mean is something about a place in Nepal, and
>> mountains. I have no idea what a recipient is going to use this for or what effect
>> it might have on them, and that has nothing to do with what I mean.
> Humpty Dumpty used words without any idea of what a recipient might use it for or what effect it might have on them.
> I think you're doing yourself a disservice by claiming you have _no_ idea. You don't have a complete and accurate idea. When you want to say something, you say enough, with enough hyperlinks and other reference material, to help the poor reader.
>>   (And this is
>> just as well, since on the Web I cannot *possibly* know what effect it might
>> have on them.)
> Of course, you can't possibly know EVERTHING about what will happen. But surely it is the writer's obligation to consider the reader.
>> Second, meaning does not depend upon persistence.
> Insofar as communication travels the speed of light or lower, there is a time delay between the writer writing and the reader reading. Sometimes it's minutes, sometimes days, weeks, months, years, decades, centuries.   Over many of those time scales, the web changes. Insofar as you intend future readers to understand what you write, you use terms that will retain some quality. Perhaps you don't mind if a blogger changes the style of their blog, as long as the content is still there. The things you don't mind changing are irrelevant to meaning, the things you mind if they change are highly correlated with meaning of the link.
>> If my
>> uncool URI changes its reference every week, then each week's meaning is
>> perfectly clear (we can suppose) even though persistence is lacking.
> See time delay above.
>> Weekly
>> magazines might be good examples. Persistence might in fact be better defined
>> in terms of reference and meaning rather than the other way around: for
>> example, RDF and SPARQL have spend some time defining notions of
>> equivalence which allow referents to change 'harmlessly' precisely because the
>> *meaning* doesnt change.
> Exactly, I just think you are looking in the wrong end of the telescope. Turn it around. Start with persistence, and tell me what you see about meaning.
>>> As long as we talk about statements (triples) or terms (uris) having
>> disembodied meaning or fail to take into account trust, error and malice, we're
>> not making progress....  and wasting time.
>> Until we do get "disembodied" meaning clear, we will never get out of the can
>> of worms far enough to even get started on these harder problems. I agree
>> they aren't afterthoughts, but they are thoughts that must come after.
> If you start with what you think is the beginning, then yes, other thoughts must come after. I'm suggesting a different starting point, since the one you've been using isn't working.
Received on Thursday, 25 October 2012 07:44:32 UTC

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