W3C home > Mailing lists > Public > public-sweo-ig@w3.org > April 2007

Re: Layer Cake

From: Kingsley Idehen <kidehen@openlinksw.com>
Date: Sun, 01 Apr 2007 09:51:31 -0400
Message-ID: <460FB8E3.20100@openlinksw.com>
CC: public-sweo-ig@w3.org

>> Ivan,
>> I really need some clarification about the Layer Cake:
>> 1. What does URI/IRI mean or imply in the context of the layer cake?
> Usage of URI-s is fundamental to the Semantic Web. It *is* the core tool
> to combine graphs. That is all... But that is essential
What are Graphs based on your comment above then?
>> 2. What does XML mean or imply (likewise) such that it occupies a slot
>> without N3, Turtle, or TriX?
> XML is not only in terms of the syntax format. It is also the fact that,
> for example, we use XML Schema datatypes or, in SPARQL, function and
> operator set that come from the XML World. Also: RDF/XML *is* has a
> large usage base, it cannot be completely taken out from the picture. By
> making it, sort of, optional on the figure, I think the right message is
> sent.
I don't see the depiction of XML conveying optionality.

What you describe above is the transcendent nature of XML relative to 
the Layer Cake.

XML is important, it permeates the Semantic Web realm at a variety of 

Why can't the reality be depicted?

>> I am very picky about this Layer Cake update because I am (and I assume
>> many others are too) really picky about clarifying the Semantic Web
>> vision and message.
>> At the start of my participation in mailing list  I made it very clear
>> that disambiguation of RDF is vital to our common goal of eradicating
>> (within reason) the dire misrepresentation of the Semantic Web vision
>> and RDF Data Model that permeates our industry at large.
>> From my vantage point:
>> 1. URIs expose Data Sources on the Web (the concept of Data Sources is
>> much easier to understand than "URI" without qualification)
>> 2. XML plays a vital role in RDF, it's critical middleware
>> infrastructure for GRDDL and other techniques for producing RDF from non
>> RDF amongst other things, I know it's the W3C's official serialization
>> etc., but none of this is congruent with its placement in the Layer Cake
>> while N3, Turtle, and TriX are left out.
>> Ironically, XML is what is good about RDF as well as what is bad about
>> RDF (from the PR and general education perspective). This point of view
>> has nothing to do with the XML itself, just everything to do with
>> inadvertent misrepresentation in the context of the RDF Data Model (an
>> integral part of the Semantic Web vision).
>> I would like to suggest the following:
>> 1. [URI/IRI (Data Sources)] as an enhancement of the [URI/IRI] box that
>> exists right now
>> 2. [RDF Data Model] as a replacement of the current [RDF Interchange: RDF]
>> Re. point 2, we need to express the role of serialization / interchange
>> and the types of serializations formats. Ideally, via little boxes
>> within the Data Model box (towards the top which indicates the point
>> where interchange occurs).
>> I think we need to resolve this matter urgently and I am hoping we can
>> arrive at some consensus via this mailing list.
> This also shows that everybody sees something different in a layercake.
> It is the elephant of the tale... The rule of URI/IRI is the core
> technology there, I do *not* see that as equivalent to data sources. I
> also do not see the reason why the Data Interchange: RDF is bad; it is
> the core goal of a particular piece of technology...
If we can define a Graph in such a way that it isn't related to Data. Or 
we can define any Resource on the Web as not being ultimately about a 
piece of Data (that may or may not have context). The I would accept and 
comprehend the URI/IRI depiction.

> I must say that I am a bit uneasy restarting the discussion on the
> layercake diagram. There has been a looong discussion (before SWEO came
> on board) on the SW Coordination Group on how to do this without
> radically changing everything and I also had a long discussion with Tim
> on that. It reflects a kind of a consensus right now... This type of
> discussion can drag on....
I am equally uneasy about using the Layer Cake as the definitive diagram 
for unraveling the constituent parts of the Semantic Web. I say this 
because the Wikipedia article is the first point of call for non 
Semantic Web specialist trying to comprehend the Semantic Web vision.

> Ivan
> - --
> Ivan Herman, W3C Semantic Web Activity Lead
> URL: http://www.w3.org/People/Ivan/
> PGP Key: http://www.cwi.nl/%7Eivan/AboutMe/pgpkey.html
> FOAF: http://www.ivan-herman.net/foaf.rdf
> Version: GnuPG v1.4.2.1 (Cygwin)
> Comment: Using GnuPG with Mozilla - http://enigmail.mozdev.org
> iD8DBQFGD0+MdR3hQzQ/Gj0RAspmAKCr+3n507BsM4VWAJtvaiibQgT5owCgxFlv
> HYT6HEgU+ljlMlFea461/FY=
> =bAI3



Kingsley Idehen	      Weblog: http://www.openlinksw.com/blog/~kidehen
President & CEO 
OpenLink Software     Web: http://www.openlinksw.com
Received on Sunday, 1 April 2007 13:51:39 UTC

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