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Quick review of paper

From: Eric Miller <em@w3.org>
Date: 10 Apr 2003 15:47:13 -0400
To: pepper@infotek.no
Cc: www-archive@w3.org
Message-Id: <1050004033.8433.228.camel@birch>

Hi Steve,

Here is a quick review of your paper for todays discussions.

--eric


Review of -

Curing the Web's Identity Crisis - Subject Indicators for RDF
http://www.ontopia.net/topicmaps/materials/identitycrisis.html
by Steve Pepper, Sylvia Schwab

by em

caveat: bumpy airplane affecting brain... warning, warning...


General comments :

1) I think the title of this work is not helpful in making the case
this paper is trying to achieve. It is immediately confrontational and
while this certainly may be the intent, I found it rather off-putting
to the larger goal of making the Semantic Web a reality.

2) I would prefer a different set of examples :)

3) overall well written paper


Specific comments:

The information resource at http://www.w3.org/People/EM/contact#me
example...

more specifically the merging of the following assertions -

<?xml version="1.0" ?>
<rdf:RDF xmlns:rdf="http://www.w3.org/1999/02/22-rdf-syntax-ns#"
         xmlns="http://www.w3.org/2000/10/swap/pim/contact#">
  <Person rdf:about="http://www.w3.org/People/EM/contact#me">
    <rdf:value>Eric Miller, em@w3.org</rdf:value>
    <mailbox rdf:resource="mailto:em@w3.org" />
    <fullName>Eric Miller</fullName>
    <personalTitle>Semantic Web Activity Lead</personalTitle>
    <company>W3C World Wide Web Consortium</company>
    <phone>614.763.1100</phone>
  </Person>
</rdf:RDF>

and

<rdf:RDF xmlns:rdf="http://www.w3.org/1999/02/22-rdf-syntax-ns#"
         xmlns:dc="http://purl.org/dc/elements/1.0/">
  <rdf:Description rdf:about="http://www.w3.org/People/EM/contact#me">
    <dc:creator>Eric Miller</dc:creator>
    <dc:date>2002/06/04</dc:date>
  </rdf:Description>
</rdf:RDF>

as the authors point out yields potentially very silly results... 

In that the resource ...

http://www.w3.org/People/EM/contact#me has a name "Eric Miller" and
http://www.w3.org/People/EM/contact#me was created by "Eric Miller" etc.

Yep. RDF as an enabling technology allows for people to due silly
things. There is nothing in the spec that will prevent uses from doing
the kind of problems identified above nor will it prevent them from
using various semantics in a less than useful manner...

e.g.

    <dc:date>a small brown fruit</dc:date>

The notion of cataloging / descriptive best practices are not
integrated into the enabling standards. These are at a separate (but
equally important) level. Best practices are community defined. The
question the authors I believe are trying to ask is are there 'best
practices' that we might suggest that will facilitate interoperability. 

This is an important question indeed to ask and explore further and
not limited only to topic of identity as discussed in this paper.


Section 3

"The root of the problem is that one URI is being used in two quite
distinct ways: to identify one subject directly and to identify
another subject indirectly. Because no syntactic distinction is made
between these two usages, an application has no way of telling them
apart and ends up getting thoroughly confused."

There is a different interpretation of the above example. And that is
that the 'metadata' and the 'data' are not uniquely identifier. Thus
it is unclear which description applies to both. 

Again from a standpoint of best practices, it is important to drive
home that metadata (as data) should be considered a first class object
and thus also be identified. Thus the problem above would have been
avoided. FOAF is a good example of a user community that has taken
this approach and one that should be highlighted as an important case
that other communities may consider following.

re URI/URI-Ref distinction that has been proposed by some in the RDF
community... The authors do point out accurately however that the use
of a '#' make it problematic to describe this an an information
resource.

The suggestion the authors (and others @@ ref @@) provide are to
differentiate URIs via different relationships with the object.

<contact:Document rdf:subject="http://www.w3.org/People/EM/contact#me">
  <dc:date>2002/06/04</dc:date>
</contact:Document>

<contact:Person rdf:indicator="http://www.w3.org/People/EM/contact#me">
  <contact:fullName>Eric Miller</contact:fullName>
</contact:Person>

note: a point of future discussion along the pedagogical / deployment
axis might be to s/rdf:indicator/rdf:about to reflect current (even if
potentially confused) practice.

note: a point regarding interop with topicmap community might be to
discuss s/rdf:subject/tm:subject in the above example



-- 
eric miller                              http://www.w3.org/people/em/
semantic web activity lead               http://www.w3.org/2001/sw/
w3c world wide web consortium            http://www.w3.org/
Received on Thursday, 10 April 2003 15:48:09 GMT

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