[XML4Lib] RDF or XML

[Jon Gorman]

> I read an article recently which suggested that RDF, rather than XML,
> may become the language of the Semantic Web.

> As a newbie, should I concentrate on RDF, or, is it too early to say?

Well, RDF and XML aren't mutually exclusive.  XML is, after all, a way
to create markup languages.  XML excels in marking up documents.  This
is in no small part due to the lessons learned from XML's
meta-language, SGML.  There's been some who complain against using XML
in more data-orientated applications and they have some valid points.

RDF, from what I understand, is a way of conveying information about
resources and relations.  In fact, if you look at the RDF specs,
you'll see it conveyed in the XML format.  I haven't studied as much
of RDF as I'd like, so I can't talk much about it.

In some senses, it's like comparing paper as a physical object and
words as an abstract concept.  It doesn't make much sense to say
"Well, I hear there's words now so now we'll get rid of paper.".  The
words have to be written down in some manner and paper is one of the
choices but not the only choice.  Whoever wrote the article might be
misunderstanding some of the hype coming out Semantic web community.

You still need a machine-readable format to process RDF.  It's
arguable whether XML is the best format, but certainly XML still
excels for things like marking up a book, etc.  From what I know,
admittedly little, of rdf is that it's not intended for things like
document markup.
The focus of RDF is how to describe things, the focus of XML is how to
indicate properties of text and identify semantic/syntactic objects in
a document.

Jon Gorman
Research Information Specialist
University of Illinois at Urbana-Champaign