A Brief Introduction To Metadata And The Semantic

(terms used, links and metadata about this article at the bottom)

The problem

Web documents lack metadata.

Sure, some sites use some of the metatags, and the title tag gets used a lot, but even this limited amount of metadata is poorly defined (what is supposed to go in that title tag anyway?) and poorly used.

This lack of metadata makes it really hard to search the web, and limits it's use. It's really hard to search for related documents for example.

The solution

The core of the World Wide Web Consortium's (W3C) metadata vision is a concept known as the Semantic Web. The semantic web means that all the stuff out there has metadata with it that describes it.

But is the W3C then going to define thousands of metatags for every possible subject? Don't think so, Jose.

Enter the Resource Description Framework (RDF).

The resource description Framework is an XML-like standard for defining vocabularies that define metadata.

These vocabularies can then be used to describe documents. There already are a bunch of vocabularies out there (mostly for describing books), that can be used, but anyone could invent a new one. Market forces decide which ones get popular.

The future

This is all of little consequence to web developers right now. But anyone involved in content management should watch this space, interesting times are ahead.

Terms used

Metadata: metadata is data about data. I'll illustrate with a few examples:

the author of a book is metadata. The category a library classifies a book in

is metadata about that book. The title argument of an tag is metadata.

Related links:

The power of metadata

http://openp2p.com/pub/a/p2p/2001/01/18/metadata.html

(a really good introduction at http://p2p.com)

What is RDF?

http://www.xml.com/lpt/a/2001/01/24/rdf.html

(really good as well at http://xml.com)

Some metadata about this article (you may have noticed, more is provided by evolt):

Author: Peter Van Dijck, aka pedrito

(for example, for meta data on the author, click on the author link at the top of the article)

Title: Introduction to metadata and the semantic web.

Inspiration: the above articles

Date of writing: Friday, January 2001

keywords: metadata, semantic web, p2p, Resource Description Framework, rdf, xml, content management.