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Re: Terminology (was Re: article on URIs, is this material that can be used by the)

From: Pat Hayes <phayes@ihmc.us>
Date: Tue, 12 Jun 2007 11:59:08 -0500
Message-Id: <p06230905c2947bb5f024@[10.100.0.28]>
To: ht@inf.ed.ac.uk (Henry S. Thompson)
Cc: Tim Berners-Lee <timbl@w3.org>, Dan Brickley <danbri@danbri.org>, www-tag@w3.org

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>Pat Hayes writes:
>
>>  HST writes:
>>>
>>>OK, so further to this and your previous response, care to define
>>>'represent', 'depict' and 'describe' as you would like to see them
>>>used in this kind of discourse?
>>
>>  'Describe' relates a textual or symbolic document to what it, well,
>>  describes. Its the basic relation between a symbolic text and some
>>  part of the (or a possible) world, aka a situation, aka an
>>  interpretation structure. It presumes that the describer has a
>>  symbolic, parsable, structure to which meaning can be attached.
>
>OK, that seems pretty straight-forward.  For example, in the WebArch
>introductory example http://www.w3.org/TR/webarch/#intro, we can say
>that the Oaxaca weather report 'describes' the weather in Oaxaca.

Right.

>
>>  So in a game, for example, the Eiffel tower jpeg might be a symbol
>>  for a goal state the players are racing to attain.
>
>What???  This seems to be an example for 'represents', not for
>'describes'. . .

My point was only that just about anything can be a 'symbol' in a 
description, not just character strings. Map symbols might be like 
little pictures, for example. Flickr and MySpace 'buddy icons' are 
symbols. The same general semantic story applies to syntactic 
structures made up of pictures, icons, wiggles, character strings or 
whatever. "inscription" is sometimes used as a generic word. So for 
example, musical notation is a descriptive notation: it has a syntax 
and is built up (not recursively, though) from simpler 'lexical' 
symbols, which are the marks on the stave.

>
>>  'Depict' relates an image to what it is an image of. "Image" here can
>>  be construed broadly, to include audio "images" (sound tracks) for
>>  example. Cameras and recorders create depictions, but they can also be
>>  made by artists of course. Typically, depictions are not constructed
>>  from symbols, they have no syntax, and they represent by being in some
>>  sense similar to (a projection of) the thing they depict. In the
>>  literature often called a "direct" representation.
>
>I'm good with this too.
>
>>  'Represent' is an overarching term meaning any relationship between
>>  some information-bearing object and the thing or things it bears
>>  information about. It encompasses both the above and probably other
>>  things as well.
>
>Hmm -- I'm less happy here.  Leaving aside the political science
>meanings, seems to me there are two primary ordinary-language meanings
>of 'represent':
>
>  1) "stands in for"/"takes the place of", as in "the yellow disk
>     represents the attacking force, the blue bar the defenders".
>
>     Here we have some kind of arbitrary, externally stipulated,
>     connection between an object or a symbol with a referent.
>
>     I think _this_ is how I would label your game/Eiffel tower jpeg
>     example.

Yes, me too: but this is just the ground, elementary case of a 
description. Its a description in a primitive language without any 
syntax. All descriptive semantics start with a mapping from the 
elementary symbols to referents, and build up from there. In this 
case, there's no more building to be done.

>  2) "corresponds in a regular way"/"re-presents", as in "The position
>     of the arrow on this dial represents the amount of fuel in the
>     tank" or "these WFFs represent propositions about the structure of
>     my family" or "this (metadata, bits) represents today's Oaxaca
>     weather report" or "the value of the variable *total* represents
>     the number of registrants for the conference to date".

But surely there are many other kinds of representation. A diagram 
represents some aspect of a building or a machine, for example, or a 
concept map represents what someone knows about Mars. Realistic 
examples often involve complex mixtures of descriptive and depictive 
elements, often intermingled in ways that are hard to disentangle.

"Represent" has certainly been used by many writers to refer broadly 
to the whole gamut of depictions, descriptions and other kinds of 
encodings of meaning. But if you can suggest an alternative general 
word I'll be happier than I am at present :-)

>
>>  I think tag-represent is a very narrow, special case of depiction, in
>>  this scheme of things.
>
>Interesting.  I think it follows from what you said above that I
>agreed with, and what I said above, that depiction is a sub-case of
>restriction(2), where, as you say, there's little-or-no 'syntax', but
>there is some kind of isomorphism.

I think we just agreed with one another.

>   In the digital world, it's almost
>always some kind of projection (e.g. from 3-D to 2-D, or from stereo
>to mono) and quantisation.

Yes, I agree that projection and quantization are often involved, but 
they don't have to be. A Xerox copy is a depiction. And the 
projection/quantization is usually from the physical to the 
representation of it (eg in cartography).

>  webarch:represents doesn't feel like that
>at all to me -- it crucially involves syntax (that's what the
>'metadata' part of the domain determines, after all), it usually
>doesn't involve sampling or quantisation, nor is there necessarily any
>kind of isomorphism.

Oh dear, then I really don't understand it after all. I thought I had 
it figured out. First, I agree it doesnt involve sampling or 
quantization or projection. But how does it involve syntax? And 
surely it does involve isomorphism. Isnt what I see in my browser 
window supposed to be in some fairly strong sense isomorphic to the 
structure of the Website I just GETted? If not, what is supposed to 
be the relationship between them?

>
>Having said that, I don't think we've gotten to the bottom of the
>ontology of the Web (in the old-fashioned sense of 'ontology' -- what
>is the nature of the things involved).  In particular, I think
>that trying to tell essentially the same story about
>
>  http://memory.loc.gov/service/pnp/cph/3c00000/3c07000/3c07700/3c07700r.jpg
>
>and
>
>  http://www.clintonlibrary.gov/bios-WJC.html
>
>and what they identify (an image of Bill Clinton and a biographical
>sketch of Bill Clinton, respectively) is to oversimplify, and to blur
>a crucial distinction, namely that a (image/jpg, bits) representation
>once rendered conformantly requires no further interpretation to be
>what it is, whereas a (text/html, bits) representation _does_ require
>interpretation.

I agree that they are different, but I think you say this wrong. 
Neither of them requires interpretation to be what they ARE. But they 
both require interpretation to be understood as ABOUT Bill Clinton; 
although we usually call it 'recognition' in the first case.

As for 'same story', I agree the detailed stories are different; but 
it remains that these can both be said to be 'representations' of 
Bill.

>
>But that's a story for another day. . .

As the milkmaid said to Thor: it is fun, isn't it?

Pat

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Received on Tuesday, 12 June 2007 16:59:17 UTC

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