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Re: Terminology for RDF Statement Sets

From: Brian McBride <bwm@hplb.hpl.hp.com>
Date: Sun, 15 Apr 2001 22:58:14 +0100
Message-ID: <3ADA1976.689945B5@hplb.hpl.hp.com>
To: Charles McCathieNevile <charles@w3.org>
CC: Sandro Hawke <sandro@w3.org>, www-rdf-interest@w3.org
Charles,

A reference to this message had added to the issues list under:

  http://www.w3.org/2000/03/rdf-tracking/#rdf-terminologicus

Brian


Charles McCathieNevile wrote:
> 
> There is an attempt within WAI to build a glossary from teh existing ones we
> are using. It would be nice to align it with a glossary for this group. (The
> idea is that terms can be extracted easily for use in specs, but that the
> collected groups  of WAI are expected to sort out an entry for each term in
> an attempt to get some consistency among us).
> http://www.w3.org/WAI/GL/2000/12/unified-glossary
> 
> And more importantly there is the work of the SWAG project (Hey Aaron, speak
> up!! <grin/>). I would like to align that, too, because I think that it is a
> smarter model and I hope it is compatible without having to do too much
> administrivia.
> 
> cheers
> 
> Charles McCN
> 
> On Fri, 13 Apr 2001, Brian McBride wrote:
> 
>   Hi Sandro,
> 
>   Sandro Hawke wrote:
>   >
>   > There's a technique in object-oriented design where you listen to all
>   > the different words people are using and then turn those words into
>   > class names.  In the RDF community, there seem to be a small number of
>   > concepts for which an large number of terms are used.  I'm going to
>   > try to list the ones I've heard, suggest what I think they mean, and
>   > generally suggest this be on the RDF Issues List.
> 
>   Thanks for bringing this up and for the discussion which follows.
> 
>   There is an issue on the list:
> 
>     http://www.w3.org/2000/03/rdf-tracking/#rdf-terminologicus
> 
>   which is basically about the need for a glossary.  Does that cover the
>   issue you wanted raisedd on the list?  I will add a reference to your
>   message to that issue.
> 
>   Brian
> 
>   ps:  I try to catch all issues raised on www-rdf-interest and
>   www-rdf-logic, but to be sure an issue you raised is picked up, its
>   better to send to www-rdf-comments@w3.org.
> 
>   B
> 
>   >
>   > As background, there are also various other terms in use for "RDF
>   > statement".  I've heard (and used) "statement", "assertion", "triple",
>   > "3-tuple", "tuple", "sentence", and "property statement", at least.
>   > But I think "RDF Statement" is okay for the formal documents and for
>   > this message.
>   >
>   > The area I'm concerned about is sets (in the mathematic, set theory
>   > sense) of RDF statements.  Let me list some of the terms I've heard,
>   > and see if I can organize them.
>   >
>   > (set itself)
>   >   statement set
>   >   graph
>   >   subgraph
>   >   model
>   >   theory   (a set of theorems; rdf statements as simple theorems)
>   >   infoset   (an RDF infoset, not an XML infoset)
>   >   dataset
>   >   corpus (a body of knowledge; term I coined some years back)
>   >   world
>   >   universe
>   >   description
>   >   semantic content  ("for is in the semantic content of document bar")
>   >   knowledge base
>   >
>   > (set storage)
>   >   triple store
>   >   repository
>   >   database  (or set itself; ambiguous)
>   >
>   > (set encoding)
>   >   context (in n3)
>   >   logical formula
>   >   document   ("does RDF document foo include RDF statement bar?")
>   >   text     (like document)
>   >
>   > (set source)
>   >   attribution
>   >   provenance
>   >
>   > (The term "model" deserves a special disambiguation: "*The* RDF Model"
>   > is the architecture, technique, or method of building things we use in
>   > the RDF community.  "*An* RDF Model" is a representation of some
>   > knowledge as a collection of RDF sentences (made according to *the* RDF
>   > Model).  I would suggest "architecture" for the former sense, and the
>   > latter sense is the subject of this message.)
>   >
>   >  * "RDF" or "RDF Statement" Specializations
>   >
>   > Some of these terms are well understood in some field, and we just
>   > want a specialization.  We can prepend "RDF" to be make our usage
>   > precise if the context does not do so.  Terms like "RDF statement set"
>   > or "RDF infoset" or "RDF statement repository" work this way.
>   >
>   > Many of these terms are defined in the appropriate sense only in some
>   > fairly narrow field or context.  For example, you need just the right
>   > setting to have the phrase "an RDF theory" understood to mean a set of
>   > RDF sentences.
>   >
>   >  * Confusing Information with its Identification
>   >
>   > We sometimes conflate a set with the attributes of the set we use to
>   > identify it, such as where it is stored and where we got it from.
>   > Contrast terms for the information itself ("dataset"), the place it
>   > exists ("repository"), the thing representing or encoding it
>   > ("document"), or the source of the information ("provenance").
>   >
>   > Quite a bit could be said about this kind of confusion.  In common
>   > usage, the term "database" is used for both a collection of data and
>   > for a database management system (a running process, or the software).
>   > Think of all the ways one might answer "What database did you use?" in
>   > different situations.
>   >
>   > This distinction is intentionally ignored in most programming systems.
>   > In C, an "int" is a C object (an area of memory) which represents an
>   > integer.  It is not actually an integer itself, of course.  In C this
>   > is rarely a problem.
>   >
>   > For us, though, it may be more pernitious.  In set theory, sets are
>   > immutable.  But we programmers are used to Set.add(element) and
>   > Set.remove(element) because we conflate mathematical sets with the
>   > data structures which can be used to store information about set
>   > membership.  To me, every term on the above list could be used in a
>   > mutable sense, because I have the programmer's habit of naming data
>   > structures (mutable or not) after the objects about which they store
>   > data.  So what term can I use to unambiguously denote the
>   > mathematically pure, immutable kind of set of RDF statements?
>   >
>   >     -- sandro
> 
> --
> Charles McCathieNevile    http://www.w3.org/People/Charles  phone: +61 409 134 136
> W3C Web Accessibility Initiative     http://www.w3.org/WAI    fax: +1 617 258 5999
> Location: 21 Mitchell street FOOTSCRAY Vic 3011, Australia
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Received on Sunday, 15 April 2001 17:58:00 GMT

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